From around 8000 BC, settlements of populations based on a primitive agricultural economy began to emerge in the eastern coastal regions and along the rich river deltas of the Huang He (Yellow River), the Yangtze, and the Wei. These civilizations focused on hunting, gathering, and fishing, and the cultivation of millet in the north and rice in the south. Each civilization is notable for its own distinct style of pottery, such as the bold earthenware of the Yangshao (5000-3000 BC) and the black ceramics of the Longshan (3000-1700 BC).