The prehistory of the Han Chinese is closely intertwined with both archaeology, biology, historical textual records and mythology. The ethnic stock to which the Han Chinese originally trace their ancestry from were confederations of late Neolithic and early Bronze Age agricultural tribes known as the Huaxia that lived along the Guanzhong and Yellow River basins in Northern China. In addition, numerous ethnic groups were assimilated and absorbed by the Han Chinese at various points in China's history. Like many modern ethnic groups, the ethnogenesis of Han Chinese was a long and lengthy process that involved the expansion of the Chinese dynasties and their assimilation of various non-Chinese ethnic groups that became sinicised over the centuries.