Zhang Shicheng was born in a coastal village near Taizhou in present-day Jiangsu. His childhood name was Zhang Jiusi, and his family had worked the salt flats and hauled salt by boat for generations. Salt was a government monopoly, so the haulers did brutal work and were still squeezed by officials and licensed merchants. In 1353, unable to bear an official's abuse any longer, he gathered his brothers and eighteen fellow salt workers and rose in revolt.
He took the city of Gaoyou, styled himself Prince Cheng, and named his state Great Zhou. In 1354 the Yuan chancellor Toghtoa surrounded Gaoyou with a huge army and the city came close to falling. Then Toghtoa, caught up in a power struggle at court, was suddenly stripped of his command in the middle of the siege, and the Yuan host scattered. That single quarrel at court saved Zhang — and with it went the Yuan's last real chance to put the rebellions down.
In 1356 he crossed the Yangtze, took Pingjiang (present-day Suzhou), and made it his base. In this, the richest land in the south, he kept taxes light and was generous to scholars and painters. For a time he even made a formal submission to the Yuan, accepted a title, and shipped grain by sea to Dadu — a choice of practical advantage over principle. In 1363 he declared himself Prince of Wu again.
But he set his mind on holding what he had rather than expanding. In 1363, while Zhu Yuanzhang staked everything against Chen Youliang at Lake Poyang, Zhang watched instead of striking at his rear. Once Chen was gone, Zhu turned on him. From the winter of 1366 Zhu's army ringed Pingjiang in layered siege works and cut off its food.
After ten months the city fell, in 1367. Zhang tried to hang himself, was found and cut down by his own officer, and was taken to Yingtian (present-day Nanjing), where he died. Some accounts say he took his own life there, others that he was beaten to death. It is said that he did not speak a word the whole way.
Suzhou remembered him for a long time. Under the Ming he could not be honoured openly, so on the thirtieth day of the seventh lunar month, when incense was offered to the bodhisattva Ksitigarbha, people quietly burned some for him as well. They called it the 'Jiusi incense', after his childhood name — a custom still told as a story today.