Liangzhe Circuit (997–1160s) was one of the major circuits during the Song dynasty (960–1279). Its administrative area corresponds roughly to modern Zhejiang, Shanghai, and southern Jiangsu (the portion east of Changzhou, between Lake Tai and the Yangtze). The fertile Yangtze River Delta lay within Liangzhe Circuit, as did Lake Tai. Liangzhe was the wealthiest circuit in Song. The capital of Liangzhe Circuit was Hang Prefecture (renamed Lin'an Prefecture in 1129, when it became the Song capital).