The name of the protohistoric tomb period of Japan, 300-710 AD, and the type of tumulus used for the burials. . Large tombs were built which were covered with artificial hillocks about 8 meters high, with burial chambers about 2 meters underneath the top surface. The burial chamber, enclosed with stones, contained coffins and various funerary offerings. The period when tombs of this kind were built in abundance was characterized by Haji ware and Sue ware. It is divided into Early, 4th century; Middle, 5th century; and Late, late 5th-7th centuries. The Kofun period falls between the Yayoi period and the fully historic Nara period and partially overlaps the Asuka and Hakuho periods of art historians. In their writings, the Kojiki and Nihon Shoki texts, the culture was explained. Early kofun were built by modifying natural hills, as were Late Yayoi burial mounds. Haji pottery, used throughout the Kofun period, is very similar to Yayoi pottery and farmers lived in the same kinds of houses, using very similar tools. Technical advances over the yayoi period include irrigation canals and dams. There were also silversmiths who made the ornaments deposited in kofun and professional potters began making Sue pottery in the 5th century. Those in the fertile and well-protected Yamato Basin actively sought new technical and administrative skills on the continent and thus artisans came to make new kinds of pottery, ornaments, and weapons. Yamato leaders gained control over much of Japan in the 7th century and moved the capital to Heijo in 710. The magnificent kofun tombs indicate that the Yamato court based in the Yamato area (the present Nara prefecture) succeeded in bringing almost the whole of Japan under its control.