While the Simovic government made every effort to maintain friendly relations with Germany, Hitler was bent on settling the issue by force of arms. Preparations for the rapid conquest of Yugoslavia were hastened so as not to jeopardize the impending campaign against Russia. Germany's limited resources precluded the possibility of tying down forces in Yugoslavia for any protracted period while simultaneously invading the Soviet Union.
The possibility of an invasion of Yugoslavia had hitherto not been considered by the German Army planners. For a better understanding of the problems with which the German General Staff officers were faced, it is necessary to examine the topographic features of that country.
The Yugoslav coastline along the Adriatic extends for approximately 400 miles and is fronted by numerous small islands. The Dalmatian Alps, which run along the coast, constitute a formidable barrier as good roads are scarce. Stretching across the peninsula, roughly from east to west, are the Balkan Mountains. The ranges are high, rough, and rugged, and are intersticed by numerous passes which, however, can be successfully negotiated by specially trained and equipped mountain troops.
The inland frontiers of Yugoslavia extend some 1,900 miles and border on Italy, Austria, Hungary, Romania, Bulgaria, Greece, and Albania. Covering a land surface approximately the size of the State of Oregon, Yugoslavia has a population of almost 14; million, of which 5 million Serbs and 3 million Croats constitute the two largest ethnic groups. In the northern part of the country a German minority element numbers about half a million. The largest cities are Belgrade, the national capital, with 400,000 inhabitants and Zagreb, the principal Croat city, with 200,000
The country can be roughly divided into five distinct natural geographic regions. The so-called Pannonina Basin, within which the national capital of Belgrade is centrally located, is by far the most important industrial portion. The Sava and Drava valleys link this area with the Slovene Alps, the forerunners of the more formidable Julian Alps. The Morava-Vardar depression extends southward from Belgrade to the Greek frontier. The Adriatic coastal belt extends from Italy in the north to Albania in the south. The Dalmatian Alps rise directly out of the sea and overshadow the central mountain or Dinaric Karst region farther inland.
There are several great routes of communication in the Balkans. One of these follows the Morava and Vardar Rivers from Budapest to Salonika and connects the Danube with the Aegean. The best roads and railroad lines are to be found in the northern and northeastern fringes of Yugoslavia which formed part of the Austro-Hungarian Empire.
Because of its difficult terrain, Yugoslavia is far from being ideally suited for the conduct of major military operations. This poorly developed, rugged, and mountainous country, with its limited routes of communication and sparsely populated area, is bound to raise havoc with an invader's communications, movements, and logistical support.
Almost all of the rivers, including the Drava, Sava, and Morava, are tributaries of the Danube, which flows through the northwestern part of Yugoslavia for about 350 miles. Soon after crossing the northern border an attacking ground force is confronted by three formidable river barriers: the Mura, the Drava, and the Sava. At the time of the spring thaws these rivers resemble swollen torrents; the Drava at Bares and the lower course of the Sava become as wide as the Mississippi at St. Louis. It is therefore of vital importance for the invader to seize the key bridges across these rivers while they are still intact.
Hitler declared that the uprising in Yugoslavia had drastically changed the entire political situation in the Balkans. He maintained that Yugoslavia must now be regarded as an enemy and must be destroyed as quickly as possible despite any assurances that might be forthcoming from the new Yugoslav Government. Hungary and Bulgaria were to be induced to participate in the operations by extending to them the opportunity of regaining Banat and Macedonia, respectively. By the same token, political promises were to be extended to the Croats, promises that were bound to have all the more telling effect since they would render even more acute the internal dissension within Yugoslavia.
In view of Yugoslavia's difficult terrain, the German plans called for a two-pronged drive in the general direction of Belgrade, with one assault force coming from southeastern Austria and the other from western Bulgaria. These forces were to crush the Yugoslav armed forces in the north. Simultaneously, the southernmost part of Yugoslavia was to be used as a jumpoff area for a combined German/Italian offensive against Greece. Vital as the early capture of Belgrade proper was considered to be, possession of the Belgrade-Nis-Salonika rail line and highway and of the Danube waterway was of
even greater strategic importance to the German supply system. Hitler therefore arrived at the following conclusions:
After this plan had been submitted to and approved by Hitler, it was incorporated into Directive No. 25.
This outline plan envisaged the following offensive operations:
During the afternoon of 29 March the Deputy Chief of Staff for Operations, Generalleutnant (Major General) Friedrich Paulus--who was to lead the survivors of the Stalingrad pocket into Russian captivity less than two years later--presided over a special conference in Vienna at which the plans of attack and timetable for the operations against Greece and Yugoslavia were discussed. Present with their respective chiefs of staff were Field Marshal List, the commander of Twelfth Army, Generaloberst (General) Maximilian von Weichs of Second Army, and Generaloberst (General) Ewald von Kleist of the First Panzer Group. Field Marshal List was brought up to date
on the changes in the situation necessitated by the Yugoslav campaign, and all commanders were fully briefed on the projected plans for the conduct of the operations. Decisions were reached as to which units were to participate in the various thrusts from Austria and Hungary under the command of Second Army. In addition, the corps headquarters and GHQ units were selected and assigned.
One of the subjects discussed during this meeting was the participation of Germany's allies and satellites in the Yugoslav campaign. Since the Italians in Albania had demonstrated their inability to mount any offensive operations and the Italian Second Army deployed in northern Italy apparently would not be ready for action until 22 April, any real assistance from that side was not to be expected. At any rate, according to the German Army Command plans, the Yugoslav operations would be almost completed by the time the Italians could be ready. The Hungarians acceded to all German requests for the use of their territory and agreed to take an active part in the operations by committing contingents, which were to be subordinated to the German Army High Command. At the conclusion of the conference, General Paulus proceeded to Budapest to discuss details of the operation with the Hungarian general staff.
Another result of the conference of 29 March was the decision to delay the initial air attacks so that they would coincide more closely with the attack on Greece. The purpose of this measure was to bring Operation MARITA into a closer relationship with Operation 25. The revised timetable thus foresaw that the attacks of Twelfth Army to the south and west and the air bombardment would be launched simultaneously on 6 April, the thrust of First Panzer Group on 8 April, and the Second Army attack on 12 April. These deadlines were adhered to with the exception of D-day for Second Army, which was moved up when the rapid successes scored by the probing attacks led to the decision of getting off to a "Hying start."
highway and railroad bridges across the Drava near Bares. In this manner the corps would be able to launch its thrust toward Belgrade by 8 April, the same time that the First Panzer Group was to attack from the southeast. One motorized column was to be diverted to the southwest with the mission of capturing Zagreb at the earliest possible moment.
Farther to the west, where the terrain becomes more and more mountainous, the LI Infantry Corps was to jumpoff on 10 April and drive in the direction of Zagreb with two infantry divisions. Here, too, limited objective attacks were to be carried out during the preceding days so that strategic points in the proximity of the frontier could be secured.
On the same day, and as soon as sufficient troops became available, the XLIX Mountain Corps was to advance toward Celje.
The First Panzer Group forces had to be reorganized and regrouped for their new mission. By using every available motor vehicle, the regrouping could be achieved within a few days. For this purpose, motor vehicles from German forces stationed in Romania and from the 16th Panzer Division, deployed behind the Bulgarian-Turkish border, had to be organized into makeshift motor transport columns and hurriedly pressed into service. The forces at the disposal of the panzer group were comparatively weak, considering the difficulties they were bound to encounter. In all probability, the Yugoslavs would concentrate their best troops in the vicinity of the capita], which was not easily accessible from the southeast. The German armor would be forced to negotiate some formidable mountain roads before reaching its objective. Thus, in the event that the Serbs established a well-organized defense system, this attack might involve considerable risk.
sectors. Moreover, the Yugoslav command intended to maintain contact with the Greek and British troops in Greece by strengthening its forces in northern Macedonia. In conjunction with a Greek attack from the south, the Yugoslav high command planned to commit the Third Army in a drive against Albania from the east. While this attack force was to push the Italians out of Albania, the other armies were to fight delaying actions if any frontier sector should be invaded by Germany. In the event of initial setbacks in the border areas, the Yugoslavs intended to conduct an orderly withdrawal into the inaccessible mountainous regions in the western part of the country, where they hoped to continue their resistance by engaging the invader in costly and time consuming guerrilla warfare.
This plan was unrealistic and therefore bound to fail. The Yugoslav Army could have escaped total annihilation only if it had operated in conjunction with the Greek and British forces and had built up a line of resistance in the extreme southern part of the country to achieve this purpose. This line should have been anchored on the Greek front in Albania in the west and on the mountains along the Greek-Bulgarian frontier in the east. This would have meant the voluntary abandonment of almost the entire national territory, a decision which no Yugoslav political leader could possibly have envisaged.
Because of the mountainous terrain along the German-Yugoslav frontier, the defense system in this area was limited to blocking main roads and key mountain passes where a German penetration was most likely to occur. It was here that most of the fortified positions had been constructed. Their size and strength varied depending on the importance of the border-crossing point and on the natural terrain features.
The divisions and brigades were not designated numerically, as is normally the case, but were named after provinces, rivers, mountain ranges, or cities. They were organized into three army groups seven field armies, and one coastal defense command. The following were their composition and primary missions on 6 April 1941:
When hostilities began on 6 April, the Yugoslav Army was still in the midst of mobilization, with sizable forces being clothed and equipped in their garrisons. As a result, the disposition of troops behind the 1,900-mile border was totally inadequate. The only units that were fully mobilized were the regular Army divisions of the Third and Fifth Armies, which were stationed along the Bulgarian border. Some of the border security battalions were on a war footing, but even they were understrength. Not until 3 April did the Yugoslavs start to shift troop units from the interior to the Bulgarian frontier. No strategic reserves whatsoever were available in the Ljubljana area in the north.
During his discussions with Yugoslav leaders in Belgrade on 1 April, General Sir John Dill, Chief of the British Imperial General Staff, found nothing but confusion and paralysis. Political leaders repeatedly stated that Yugoslavia was determined not to take any steps that might provoke a German armed attack. Obviously, the Yugoslav ministers failed to realize the imminence of their country's peril. Their mood and outlook left Dill under the impression that they believed they would have months to make their decisions and enforce their plans, whereas in reality only a few days were to elapse before the Germans launched their attack.
Accompanied by his close entourage and the forward echelon of the National Defense Branch of the Armed Forces Operations Staff, Hitler departed from Berlin on the evening of 10 April. On the following day the Fuehrer arrived at a small station on the single-track railroad line leading from Wiener Neustadt southward to Fuerstenberg (fifty miles east of Graz). There, his special train and that of the National Defense Branch halted in front of the northern and southern exits respectively of a tunnel that leads through the Alps south of Aspang.
From these locations the trains could easily be pulled into the tunnel in the event of enemy air attacks. While the two trains remained in the area, the entire line was blocked to normal traffic. It was from this vantage point that Hitler directed the Balkan campaigns until 25 April, when he returned to Berlin.
Between November 1940 and February 1941, a force of over 400 planes, including long-range bombers, dive-bombers, fighters, and reconnaissance aircraft, had gradually been built up in Romania and Bulgaria. By 27 March, when the Yugoslav revolt occurred, there were 135 fighter and reconnaissance planes in Romania, and 355 bombers and dive-bombers in Bulgaria.
Early in April additional air reinforcements were rushed to the Balkans. From as far away as France, Africa, and Sicily about 600 aircraft of all four types were brought up and readied for action within ten days. The fighter and reconnaissance craft were sent to fields near Arad, Deva, and Turnu-Severin in western Romania, all within easy striking distance of Belgrade. The long-range bombers were to operate from fields at Wiener Neustadt and near Sofiya, northwest and southeast of the Yugoslav capital, at 200 and 100 miles distance, respectively.
The movements from Vienna and Passau through the Alps into the detraining areas around Graz and into western Hungary presented more complicated problems. Since the capacities of the feeder lines and detraining points were considered inadequate, some elements were forced to detrain in Vienna and Salzburg and continue the movement to the assembly areas by road.
The Graz area and western Styria were particularly difficult to reach. Here, the feeder lines traversed the Alps and were consequently of very limited capacity. For this reason it became imperative to include the western tip of Hungary as assembly area for some of the German attack forces. After Hungary had agreed to the use of its territory, the assembly of the German Second Army proceeded as follows:
The daily detraining capacity of the Bruck-Graz-Klagenfurt area was seventy-eight trains, or the equivalent of the combat elements of two infantry divisions. Consequently, all of the rear echelon elements of these divisions had to detrain in the Vienna area, capable of handling 144 trains a day, and in Salzburg, where forty-eight additional trains could be unloaded. The divisional service units then had to reach the assembly areas by marching overland. However, since road conditions were poor at this time of the year, snow-clearing detachments had to be provided to keep the Salzburg-Liezen-Bruck and Vienna-Bruck-Graz roads clear. The same roads also had to be used by those divisions that moved solely by motor transportation. Since rigid traffic control was enforced and traffic regulations were strictly adhered to, the execution of these movements did not entail any undue delay.
The above-mentioned capacity figures of railroads and highways were eventually reached, but not before many difficulties had been overcome. The main problem was that no preparatory work had been started until the evening of 27 March. The system of classifying all major railroad lines according to their capacity, introduced at the beginning of the war, and the method applied in processing military rail movements both proved efficient during this emergency. The maximum performance schedule, which required the almost complete stoppage of all nonmilitary traffic, had to be resorted to only on the Austrian railroads. Aside from conserving personnel and materiel, the adherence to normal train schedules whenever possible permitted the Germans to camouflage the movements to the assembly areas right up to the time when the first contingents arrived at the detraining points.
The cooperative attitude of the Hungarian transportation personnel made it possible to increase the capacity of the Nagykanizsa detraining area in record time. The German Movement Control headquarters in Budapest, recently transferred from Bratislava, was responsible for the preparations that had to be completed within three days. All loading ramps in the area had to be enlarged and reinforced to handle heavy loads, new sidings had to be laid, and adequate antiaircraft protection had to be provided. To increase the capacity of the railroads in Hungary and Bulgaria, the Army railroad transportation agencies formed a reserve pool of locomotives and box cars suitable for troop transports.
Special measures also had to be taken to ensure the flow of supplies into the Balkans once the campaign had started. The line Belgrade-Nis-Salonika, the only one capable of handling fully loaded trains, was vitally needed for this purpose. Railroad engineer troops and construction equipment had to be reserved for the immediate restoration of this line after it had fallen into German hands.
The Bulgarian railroads were connected with the Belgrade-Nis-Salonika line. To avoid time consuming reloading operations, troop and supply trains destined for Bulgaria were loaded at "Balkan Capacity," which was two-thirds of the normal weight. This necessitated a rearrangement of the loading and unloading schedules, which was accomplished with the cooperation of the Bulgarian General Staff and railroad authorities.
military operations as well as on the extent of demolitions and mine obstacles.
At the defile of the Iron Gate, where the Danube forms the boundary between Yugoslavia and Romania, a fairly long stretch of the river is canalized. Because of the numerous locks and dams this portion of the river was considered to be extremely vulnerable. It was known that the Yugoslavs had prepared some acts of sabotage along the Danube and intended to mine the Iron Gate. Therefore, a reinforced German engineer battalion, forming part of the military mission stationed in Romania, was assigned the task of seizing and protecting this vital area.
According to a digest of captured Yugoslav documents that was written by the Foreign and Counterintelligence Office of the Armed Forces High Command after the conclusion of the campaign, there existed a plan for blocking the Iron Gate in order to paralyze German Danube shipping. This plan, said to have been prepared by British agents in April 1940, failed because of German watchfulness. The British allegedly planned to sink cement barges in the Danube shipping channel. Moreover, they were supposed to have organized a network of local agents who were to destroy port facilities and military installations and sabotage German ships while they were in Yugoslav ports.
During the Balkan campaigns the Danube actually did not play a major role as a military route of transportation. The available shipping facilities were barely sufficient for the transportation of essential materials. Although the military transportation agencies had repeatedly pointed to the urgency of a large-scale construction program of Danube vessels, Hitler had refused to allocate the necessary steel for this purpose.
Providing Second Army with the necessary supplies presented no particular problems and caused no delay in the launching of the operations. When surgical hospitals failed to arrive, for example, they were replaced by additional hospital trains.
The logistical planning was greatly facilitated by the establishment of a supply base near Vienna during the summer of 1940. Soviet political activities in the Balkans had prompted the Army High Command to stockpile large quantities of supplies at the gateway to southeastern Europe . The existence of this base made it possible to meet the sudden and unexpected demands of the Yugoslav campaign without shifting supplies from the interior of Germany, a step that would have delayed the operation considerably.
Toward the end of March 1941 no forces other than a few infantry divisions were available in Germany for immediate commitment. Those armored and motorized infantry divisions that happened to be in Germany at the time were in the process of activation, reorganization, or rehabilitation. The mobile divisions needed by Second Army therefore had to be drawn from France and the Russian border, and their transfer to the Balkans could easily have resulted in delays. The only available mountain division, whose employment was essential for the successful conduct of the Yugoslav campaign, had to be brought east from France. Similar difficulties were encountered in assembling the necessary GHQ units and artillery, engineer, and service troops. The following chart shows the problem involved in assembling the divisions assigned to Second Army:
|Assembly of Second Army Units|
|Unit||Stationed in--||Means of transportation|
|Second Army HQ Staff||Germany||Organic.|
|8th Panzer Division||France||Railroad and Organic.|
|14th Panzer Division||Russian border||Railroad and Organic.|
|16th Motorized Inf. Div.||France||Railroad and Organic.|
|1st Mountain Division||France||Motor Transportation.|
|79th Infantry Division||France||Railroad.|
|101st Light Inf. Div||Czechoslovakia||Motor Transportation.|
|125th Infantry Division||Germany||Railroad.|
|132d Infantry Division||Germany||Railroad.|
|183d Infantry Division||Germany||Railroad.|
The actual movements of these units took place in the following manner: Using organic transportation, Second Army headquarters moved from Munich to Radegund, near Graz, on 2 April. The XLIX Mountain Corps was expected to arrive in its assembly area on 4 April. After its transfer from France to Germany the 1st Mountain Division moved by motor transportation from Landaberg, northeast of Berlin, to Vienna. On 5 April the forward echelon of the division was ordered not to dismount in Vienna as previously planned, but to continue the movement to its assembly area near Klagenfurt, where it was to arrive by the evening of 8 April. However, the bulk of its combat elements did not get to Klagenfurt until 9 April, the eve of D-day, while most of the service troops joined the division piecemeal between 13 and 15 April, well after the start of operations.
Whereas LI Corps headquarters arrived in its assembly area in good time, the divisions under its command encountered many difficulties. The 132d and 183d Infantry Divisions had been ordered to entrain on 2 April. By 6 April about two-thirds of each division had detrained in Graz, and both were completely unloaded by 9 April. Meanwhile, a truck transportation regiment, then located in Paris, was ordered to proceed to Czechoslovakia from where it was to move the 101st Light Infantry Division to its assembly area. Advance elements of this division were to be in line by 9 April. However, icy roads delayed the movement to such an extent that the tail elements did not reach their destination until 15 April.
The efforts made to speed up the concentration of LII Infantry Corps were of little avail. By 11 April, after the attacks were well under way, the Army High Command was still in the dark as to when this corps, including the 79th and 125th Infantry Divisions, might
become operational. Eventually the former division was transferred to XLIX Mountain Corps, while the latter, remaining under the command of LII Corps, was held in reserve. It was 12 April when the first ten trains carrying the 79th Infantry Division pulled into the assembly area.
Only the assembly of XLVI Panzer Corps went according to schedule. The advance echelon of the 16th Motorized Infantry Division arrived in Vienna by rail on 8 April and immediately proceeded from there to the concentration area in Hungary by organic transportation. By the evening of 7 April, the 14th Panzer Division arrived in Nagykanizsa, while the 8th Panzer Division assembled its forces to the north of Lake Balaton. Although the snow had melted, the movements of all three divisions were hampered by heavy rains, and it was necessary to employ additional traffic control elements to avoid undue stoppages. However, when the lead elements of the 16th Motorized Infantry Division arrived in their assembly area on 9 April, the XLVI Panzer Corps was the only major Second Army command whose units were fully prepared to jumpoff on D-day.
The weak Yugoslav Air Force and the inadequate flak defenses were quickly wiped out by the first wave, permitting the dive-bombers to come down to roof-top levels. Against the loss of but two German fighters, twenty Yugoslav planes were shot down and forty-four were destroyed on the ground. When the attack was over, more than 17,000 inhabitants lay dead under the debris. This devastating blow virtually destroyed all means of communication between the Yugoslav high command and the forces in the field. Although some elements of the
general staff managed to escape to one of the suburbs, coordination and control of the military operations in the field were rendered impossible from the outset.
Having thus delivered the knockout blow to the enemy nerve center, the VIII Air Corps was able to devote its maximum effort to such targets of opportunity as Yugoslav airfields, routes of communication, and troop concentrations, and to the close support of German ground operations.
Early in the morning of 8 April, the First Panzer Group jumped off from its assembly area northwest of Sofiya. Crossing the frontier near Pirot, the XIV Panzer Corps, spearheaded by the 11th Panzer Division, followed by the 5th Panzer, 294th Infantry, and 4th Mountain Divisions, advanced in a northwesterly direction toward Nis. Despite unfavorable weather, numerous road blocks, and tough resistance by the Yugoslav Fifth Army, the 11th Panzer Division, effectively supported by strong artillery and Luftwaffe forces, quickly gained ground and broke through the enemy lines on the first day of the attack. The Yugoslav army commander was so greatly impressed by this initial German success that he ordered his forces to withdraw behind the Morava. This maneuver could not be executed in time because, as early as 9 April, the German lead tanks rumbled into Nis and immediately continued their drive toward Belgrade. From Nis northwestward the terrain became more favorable since the armored columns could follow the Morava valley all the way to the Yugoslav capital.
South of Paracin and southwest of Kragujevac Yugoslav Fifth Army units attempted to stem the tide of the advance but were quickly routed after some heavy fighting. More than 5,000 prisoners were taken in this one encounter.
Meanwhile, the 5th Panzer Division became temporarily stalled along the poor roads near Pirot. After the division got rolling again, it was ordered to turn southward just below Nis and cut off the enemy forces around Leskovac. When it became apparent that the Nis front was about to collapse, the 5th Panzer Division reverted to the direct control of Twelfth Army and joined the XL Panzer Corps for the Greek campaign.
Timed to coincide with the armored thrust of the XIV Panzer Corps from the southeast, the XLI Panzer Corps drive led across the southeastern part of the Banat and toward the Yugoslav capital. This attack was spearheaded by the Motorized Infantry Regiment "Gross Deutschland," closely followed by the 2d SS Motorized Infantry Division. After crossing the frontier north of Vrsac, advance elements entered Pancevo on 11 April. Having meanwhile advanced to within about forty-five miles north of Belgrade, the main body of XLI Panzer Corps met with only isolated resistance on the following day as it raced toward the enemy capital.
When the Luftwaffe launched its attacks on 6 April, the German Second Army was just beginning to assemble its attack forces along the northern Yugoslav frontier preparatory to its projected jumped on 10 April. In an effort to improve their lines of departure, some of the Second Army units took advantage of the interim period by launching limited-objective attacks all along the frontier zone. The troop commanders had to keep their forces in check to prevent major engagements from developing prematurely, which might subsequently have impaired the army's freedom of action and jeopardized the conduct of operations.
The Army High Command was determined to seize intact the principal bridges in the XLVI Panzer Corps zone. Therefore, as early as 1 April, corps elements were ordered to capture the bridge at Bares and the railroad bridge about ten miles northeast of Koprivoica by a coup de Ann.
By early evening of 6 April, the lack of enemy resistance and the overall situation seemed to indicate that the Yugoslavs would not make
That the plight of the enemy was becoming more and more desperate could be gathered from the following appeal that General Simovic broadcast to his troops:
All troops must engage the enemy wherever encountered and with every means at their disposal. Don't wait for direct orders from above but act on your own and be guided by your judgment, initiative, and conscience.
On 11 April the 8th Panzer Division reached the Osijek region, while the 16th Motorized Infantry Division farther back was advancing beyond Nasice. Numerous bridge demolitions and- poor roads retarded the progress of both divisions, whose mission it was to attack the rear of the Yugoslav forces that faced XIV Panzer Corps, and to establish early contact with the First Panzer Group.
At 0230 on 12 April, the 8th Panzer Division entered Mitrovica after two vital bridges across the Sava had been captured intact. The division continued its thrust with the main body advancing toward Lazarevac, about twenty miles south of Belgrade, which was the designated link-up point with First Panzer Group.
On the afternoon of 12 April, the XLVI Panzer Corps received new orders. According to these, only elements of the 8th Panzer Division were to continue their eastward drive to seize and secure the Sava bridge near the western outskirts of Belgrade. At 1830 the main body
Meanwhile, both the Second Army and the Army High Command were anxiously awaiting news of the fall of Belgrade. Of the three converging armored forces, XLI Panzer Corps was last reported closest to the capital, having reached Pancevo on the east bank of the Danube about ten miles east of the city. South of Belgrade resistance stiffened as the 11th Panzer Division, spearheading the First Panzer Group forces, neared the capital.
Since three separate attack forces were converging on Belgrade simultaneously, the Army High Command was not immediately able to determine which force was the first to reach the enemy capital. Toward early evening of 12 April, SS-Obersturmfuehrer (1st Lt.) Klingenberg of the 2d SS Motorized Infantry Division, finding all Danube bridges destroyed, took an SS patrol across the river in captured pneumatic rafts. The patrol entered the city unmolested, and at 1700 hoisted the Nazi flag atop the German legation. About two hours later the mayor of Belgrade officially handed over the city to Klingenberg who was accompanied by a representative of the German Foreign Ministry, previously interned by the Yugoslavs.
At Second Army headquarters, no word from the 8th Panzer Division elements, which were last reported approaching the western outskirts of Belgrade, had been received for twenty-four hours. Finally, at 1152 on 13 April the following radio message came through from the operations officer of the division:
During the night the 8th Panzer Division drove into Belgrade, occupied the center of the city, and hoisted the Swastika nag.
However, since better communications had existed between Second Army and First Panzer Group, the following flash was received shortly before the 8th Panzer Division message came in:
Panzer Group von Kleist has taken Belgrade from the south. Patrols of Motorized Infantry Regiment "Gross Deutschland" have entered the city from the north. With General von Kleist at the head, the 11th Panzer Division has been rolling into the capital since 0632.
Thus the race for Belgrade ended in a close finish with all three forces reaching their objective almost simultaneously. With the fall
of the city, the First Panzer Group was transferred from the Twelfth to the Second Army, while the XLVI Panzer Corps was placed under the direct command of the panzer group for the next phase of the operation-the pursuit and final destruction of the remnants of the Yugoslav Army.
Under the code designation "Feurzauber," units composed of cadre personnel and recently inducted trainees were organized into several waves of special assault troops. The elements comprising the first wave consisted of four battalion staffs commanding nine rifle companies, two mountain artillery batteries, one self-propelled medium artillery battery, two mountain engineer platoons, four antitank companies, and three signal and four bicycle platoons. Additional waves were subsequently formed, involving altogether about two-thirds of a mountain training division plus some attached specialist troops.
Originally these units were merely to reinforce the frontier guards and cover the gradually assembling Second Army forces along the southern border of Carinthia and Styria. This purely defensive mission, however, did not satisfy the aggressive commanders of the special assault units. Between 6 and 10 April, they took upon themselves to conduct numerous raids deep into enemy-held territory and to seize and hold many strong points along the border, thereby contributing to the rapid success of the offensive proper.
The first wave of assault units moved south from Graz in the direction of the Yugoslav border on 27 March. One of them, designated "Force Palten" after the captain in command, was assembled near Spielfeld during the first days of April. Its original mission was to secure the frontier and the vital bridge across the Mura near Spielfeld. However, on the evening of 5 April the force started to attack bunkers and enemy-held high ground across the frontier. By the morning of 6 April several hills had been taken, and scouting patrols probing deep into the bunker line south of Spielfeld made contact with the enemy. They determined the enemy's strength and disposition in the outpost area, and then broke contact. Most of the high ground remained in German hands as the enemy failed to counterattack. Then, toward 1600, mountain engineers destroyed isolated enemy bunkers without any preparatory artillery fire.
After forming raiding parties on the south bank of the stream, Captain Palten continued to move southward. During the evening he entered Maribor at the head of his force and occupied the town without opposition. Much to their disappointment, the raiders were ordered to withdraw to the Spielfeld area, where they had to sit out the remainder of the Yugoslav campaign performing guard duty at the border. Losses incurred by Force Palten were one killed and two wounded, while they captured more than 100 prisoners and much booty.
On 6 April the ELI Corps crossed the Yugoslav border at Murk and Radkersburg and seized both bridges across the Drava intact. During these probing attacks the 132d Infantry Division occupied the Sejanska stream and the 183d Infantry Division took 300 prisoners. A bicycle detachment of the latter entered Murska Sobota without encountering resistance. Since the Yugoslavs were giving ground all along the line, the corps wanted to exploit the situation. The Second Army, however, felt compelled to order both divisions to hold in place and consolidate their newly won bridgeheads. The two divisions would have to wait until their remaining elements had detrained in the assembly areas.
During the following three days the LI Corps expanded its bridgeheads, the 132d Infantry Division occupying Maribor and the 183d probing beyond Murska Sobota. Air reconnaissance reports indicated that the Yugoslav Seventh Army forces employed in this sector were withdrawing southward along the narrow mountain roads leading to Zagreb. Apparently only a thin security screen had been left in place to maintain contact with the German forces in the bridgeheads.
The Second Army thereupon ordered LI Corps to form flying columns composed of motorized elements and pursue the retreating Yugoslav forces in the direction of Zagreb. On 10 April cold winds and intermittent snowstorms hampered the movements of the advancing Germans, and flood waters interrupted the crossings at Maribor during the day. After regrouping its forces south of the
On 6 April, while the 1st Mountain Division was still on the approach march, the 538th Frontier Guard Division, stationed along the northwestern part of the Slovenian border, succeeded in seizing important mountain passes, hills, and tunnels in Yugoslav territory. During the night of 9-10 April the combat elements of the 1st Mountain Division, which had detrained only a few hours earlier, began to cross the frontier near Bleiburg. Advancing in the general direction of Celje the division spearheads stood about twelve miles northwest of the town by nightfall. After exhausting marches and some hard fighting the 1st Mountain Division took Celje on 11 April. Emissaries of the newly formed Slovenian Government asked the corps commander for a cease-fire. In anticipation of just such developments, Hitler had previously authorized field commanders to accept the surrender of individual units.
Early on the morning of 10 April, with dive-bombers clearing the route of advance, the 14th Panzer Division of XLVI Panzer Corps, split into two armored forces, broke out of the Drava bridgehead and advanced southwestward toward Zagreb, the state capital of Croatia. This attack preceded the XLVI Panzer Corps main attack toward Belgrade and was intended as a diversion.
Although large enemy concentrations had been spotted in front of the division, air reconnaissance revealed that these forces were rapidly withdrawing westward toward Zagreb. Though fierce at first, enemy resistance soon crumbled as German tanks came closer to their objective. However, extremely cold weather and snow-covered roads hampered progress to some degree. By 1930 on 10 April the lead tanks of the 14th Panzer Division reached the outskirts of Zagreb, after having covered a distance of almost 100 miles in one day.
In some instances Croat troops refused to fight, abandoned their weapons, deserted their positions, and either surrendered or simply went home. One German regiment surprised an enemy unit which was still in garrison and not yet fully mobilized. A regimental officers' party just in progress was interrupted only long enough to consummate a quick surrender, whereupon the festivities continued as though nothing unusual had happened.
On 11 April the newly formed Croatian Government called on its nationals to cease fighting and requested that they be immediately released by the Yugoslav Army. During the evening hours the first LI Corps elements entered Zagreb from the north and relieved the 14th Panzer Division.
On 12 April elements of the 14th Panzer Division linked up with the Italians at Vrbovsk. The line Novo Mesto-Slunj-Bihac-Livno was designated as the boundary between the German and Italian Second Armies south of the Sava. Occupation of the territory west of this line was assigned to the Italians. However, for the time being the German units on the extreme right wing of XLIX Mountain Corps were authorized to operate in the Italian zone.
Upon moving its command post to Maribor on 11 April, the German Second Army headquarters received a message from the Hungarian Third Army by which it was notified that Hungarian troops
were crossing the Yugoslav frontier north of Osijek and near Subotica. On the next day the Hungarians pursued the retreating Yugoslav First Army and occupied the area between the Danube and Tisza Rivers, meeting virtually no resistance.
As early as 12 April both the XLIX and LI Corps had closed up and regrouped their forces along the Sava River. Sarajevo, located in the heart of Yugoslavia, was to be the focal point upon which the German forces were to converge. Accordingly, Second Army reorganized its forces into two separate pursuit groups. Under the command of the recently arrived LII Infantry Corps headquarters, the western group consisted of four infantry divisions under the XLIX and LI Corps as well as the 14th Panzer Division, the formation that was to spearhead the drive on Sarajevo from the west. The eastern pursuit force, under the command of the First Panzer Group, was composed of six divisions, with the 8th Panzer Division leading the drive toward Sarajevo from the east. The Fourth Air Force, continuing to operate in support of the ground operations, was ordered to neutralize the anticipated enemy troop concentrations in the Mostar-Sarajevo sector.
On the afternoon of 13 April Second Army moved its command post to Zagreb to facilitate communication with the two pursuit groups and direct the mopping-up phase of the campaign from this central location. The boundary between the German Second and Twelfth Armies was the line extending laterally across Yugoslavia from Sofiya via Prizren up to and along the northern border of Albania.
By the evening of 13 April there was no longer any semblance of enemy resistance in front of XLIX and LI Corps. The main body of the German forces reached the Kupa River and some elements were quickly put across. The 14th Panzer Division, meanwhile, sped southeastward toward Sarajevo. As the division approached its objective,
reports began to circulate that open hostilities had broken out between Serbs and Croats in Mostar. German planes were quickly diverted to this area where they blasted Serb troop concentrations for three hours. By 14 April the fighting between the Serb and Croat factions had gained momentum and had spread throughout Dalmatia. On that day the 14th Panzer Division reached Jajce, approximately fifty miles northwest of Sarajevo, while forward elements of the LI Corps, attempting to keep up with the armor, arrived at the Una after strenuous marches and established several bridgeheads across the stream.
In the zone of the eastern group, one armored division combed out the sector south of Belgrade, while two infantry divisions cleared the industrial region in and around Nis. The 8th Panzer Division led the way southwestward toward Sarajevo, closely followed by two motorized infantry divisions which were driving hard toward the heart of Yugoslavia, one via Zvornik, the other from Uzice. Among the vast amount of booty were seventy-five enemy aircraft still intact on the ground. During the operations on 14 and 15 April, prisoners were taken by the thousands. North of Nis the Germans captured 7,000; in and around Uzice, 40,000; around Zvornik 30,000 more; and in Doboj another 6,000.
On 15 April both pursuit groups of Second Army closed in on Sarajevo. As two panzer divisions entered the city simultaneously from. west and east, the Yugoslav Second Army, whose headquarters was in Sarajevo, capitulated. Leaving only security detachments in the city to await the arrival of the infantry forces, both divisions continued to race southward in close pursuit of fleeing enemy remnants.
Late on the evening of 14 April, a representative of the Yugoslav Government approached the First Panzer Group headquarters and asked General van Kleist for an immediate cease-fire. When the Army High Command was advised of this turn of events, it designated
the Second Army commander, General von Weichs, to conduct the negotiations in Belgrade.
During the afternoon of the following day von Weichs and his staff arrived in Belgrade and drew up the German conditions for an armistice based on the unconditional surrender of all Yugoslav forces. The next day a Yugoslav emissary arrived in the capital, but it turned out that he did not have sufficient authority to negotiate or sign the surrender. Therefore, a draft of the agreement was handed to him with the request that competent plenipotentiaries be sent to Belgrade without delay in order to avoid unnecessary bloodshed. To expedite matters, a plane was placed at his disposal.
The armistice was concluded and signed on 17 April. (general von Weichs signed for the Germans, with the Italian military attache in Belgrade acting on behalf of his country. The Hungarians were represented by a liaison officer who, however, did not sign the document since Hungary was technically "not at war with Yugoslavia." Foreign Minister Cincar-Marcovic and General Milojko Yankovic signed for the Yugoslavs. The armistice became effective at 1200 on 18 April 1941, just twelve days after the initial German attack was launched.
The Germans took some 254,000 prisoners, excluding a considerable number of Croat, German, Hungarian, and Bulgarian nationals who had been inducted into the Yugoslav Army and who were quickly released after screening.
In reviewing the operation the following facts stand out:
Both commanders and troops of the Italian Second Army lacked aggressiveness and initiative. Moreover, the Italian command demonstrated little tactical know-how and failed to comprehend German strategic concepts. Its intelligence system was poorly developed and often tended to overestimate enemy strength and capabilities. During the entire campaign the Italians, as well as the Hungarians, displayed great reluctance to attack until the enemy had been soundly beaten and thoroughly disorganized by the (Germans.
The infantry divisions that had to fight their way through mountainous terrain in northwestern Yugoslavia accomplished their missions relatively well. It would have been advantageous, however, if the divisions had been more familiar with the peculiarities of mountain warfare. Advance detachments played an important role, but were only formed when the need arose, and again disbanded once their specific mission was accomplished.
After the initial penetrations had been achieved, powerful armored wedges exploited the situation by breaking through at various points and swiftly moving deep into the enemy rear. It was here that German motorized equipment surpassed all expectations by covering great distances with lightning speed over primitive, winding roads and through narrow, treacherous mountain passes. Road and weather conditions, especially in the mountains, demanded the careful organization of march columns, and the proper employment of traffic control units. There can be no doubt that it was the rapid thrusts of the mechanized columns across the mountains that broke the back of enemy resistance and spelled the early doom of the Yugoslav Army.
Hitler had aggressive designs on the Balkans. The campaigns of 1939 and 1940 should also have taught the Yugoslavs that German operations were invariably spearheaded by coordinated efforts of Luftwaffe and panzer units.
The idea of completely stopping a force so vastly superior in men and materiel could of course not have been entertained. However, sufficient resistance could have been mustered to gain time to permit allied forces to come to Yugoslavia's aid. The mountainous terrain in the Balkans gives the defender a certain advantage over a highly mechanized attack force. That Yugoslav defenses should have been better prepared is quite obvious. Some of the artificial obstacles encountered in the German Second Army zone indicated that efforts in that direction had been made, but were either insufficient or came too late.
When the German forces struck, the mobilization and concentration of Yugoslav defense forces had hardly begun. Instead of massing their forces around strategic points and behind natural terrain barriers in an effort to conserve strength and operate along interior lines of communication, the Yugoslav command chose to scatter its forces and spread them along the entire perimeter of the country's frontier. Thus, by attempting to hold everywhere, the Yugoslavs lost everything.
In the ground fighting, shortly after the Germans attacked, entire Croat units simply threw away their weapons and quit. In some instances, Croat officers led their men in organized attacks against Serb elements that ware actively resisting the invaders. On 8 April, Croat troops openly revolted in Vinkovci, the main railroad junction along the vital Belgrade-Zagreb line. They launched a concerted attack against the headquarters of First Army Group and held as prisoners its commander with his entire staff until they were rescued by loyal Serb troops. Such occurrences were not unusual and happened in other sectors as well.
In a letter Mussolini wrote to Hitler on 29 December 1941, the former stated with reference to Yugoslavia:
Before next spring every nucleus of insurrection must be wiped out or else we run the risk of having to fight a subsidiary war in the Balkans. The first territory to be pacified is Bosnia, then Serbia and Montenegro. The military operations must be conducted with great determination and must lead to a real and complete disarmament of the population, this being the sole guarantee I for avoiding surprise in the future. For this purpose our military forces must cooperate according to a common plan to prevent duplication of effort and achieve the desired result with a minimum of manpower and materiel.