The first settlers of Japan, the Jomon people (circa 11,000-circa 300 BC), named for the cord markings that decorated the surfaces of their clay vessels, were nomadic hunter-gatherers. They built simple houses of wood and thatch set into shallow earthen pits to provide warmth from the soil, and crafted pottery storage vessels and clay figurines called dogu. The next wave of immigrants was the Yayoi people, named for the district in Tokyo where remnants of their settlements first were found. These people, arriving in Japan about 350 BC, brought their knowledge of wetland rice cultivation, the manufacture of copper weapons and bronze bells (dotaku), and wheel-thrown, kiln-fired ceramics.
The third stage in Japanese prehistory, the Kofun, or Tumulus, period (circa AD 250-552), represents a modification of Yayoi culture, attributable either to internal development or external force. In this period diverse groups of people formed political alliances and coalesced into a nation. Typical artifacts are bronze mirrors, symbols of political alliances, and clay sculptures called haniwa, erected outside tombs.