Xúzhōu

Xúzhōu occupies a meeting place of routes on the great plain between northern and southern China, where the Sì and Yí rivers once flowed near its walls. From 1128 the Yellow River had taken over the Huái bed, so that the city sat on a vital but flood-prone stretch of waterway. In August 1351 the Red Turban leader Lǐ Èr, called Sesame Lǐ, seized the city; in 1352 the Yuán chancellor Tuōtuō retook it and massacred its people, and Xúzhōu was demoted from route to the lesser Wǔ'ān Prefecture. Under the Míng it was a directly governed prefecture, and the Qīng raised it to a full prefecture in 1733.

In 1624 the Yellow River broke its banks nearby and flooded Xúzhōu. Water filled the city and destroyed the walls built in the early Míng. Repeated floods left layers of silt over the older streets, while the need to keep grain boats moving on the Grand Canal drove successive attempts to control the river.