Hangzhou was made the seat of the prefecture of Hang in AD 589, entitling it to a city wall which was constructed two years later. By a longstanding convention also seen in other cities like Guangzhou and Fuzhou, the city took on the name of the area it administered and became known as Hangzhou. Hangzhou was at the southern end of China's Grand Canal which extends to Beijing. The canal evolved over centuries but reached its full length by 609.[17]In the Tang dynasty, Bai Juyi was appoint...