Tang Dynasty Grand Canal Shipping System

Timeline

1. 701–741Bian River–Luo River grain route · Central PlainsDuring the Kaiyuan reign the grain transport system was complete; Jianghuai zu-yong-diao tax grain moved north via Yangzhou and Bianzhou, transferred at the Yellow River into the Luo River to reach the eastern capital, then west to Guanzhong; granaries, locks, dams, and transport expeditors were set up along the route, with annual shipments reaching millions of shi.
2. 755–780Bian River and Jianghuai grain routes · JianghuaiAfter the Hebei military commissioners carved out autonomous domains, the grain route north of the Yellow River was blocked and the court relied more on Jiangnan revenues; Liu Yan reformed grain transport, implementing sectional relay via the 'Jiang, Bian, He, Wei' method, with Yangzhou as the grain assembly center.
3. 780–800Terminus of the Guanzhong grain canal · ShaanxiAfter the two-tax system was introduced, grain payments were converted to cash and grain transport supplied the capital mainly in kind; transfer commissioners and grain canal maintenance became fiscal priorities; though the military commissioners were restive during the Zhenyuan reign, the Grand Canal system remained the lifeline linking Jiangnan and Guanzhong.