Huáihǎi

Huáihǎi culture occupies the plain around Xuzhou, where Jiangsu, Shandong, Henan and Anhui meet, between the Shandong hills and the Huai basin on the lower Si and Yi rivers. Its chief city Pengcheng was the ancestral home of the Han imperial house and Xiang Yu's Western Chu capital in 206 BCE, later a garrison of the southern dynasties.

The Jurchen took it in 1129, and in 1352 chancellor Toqto retook it from Red Turban rebels to keep grain routes open. Ming Xuzhou held a Grand Canal granary and one of seven customs barriers, drafting tens of thousands of households to haul tribute boats through the Yellow River rapids.

The Jia Canal of 1605 bypassed the city and began its commercial decline; a 1624 flood buried the walled city under four metres of water and silt, and the Qing took it in 1645. After the 1668 Tancheng earthquake, Xuzhou became a Qing prefecture in 1733 over the old Huaihai plain counties.