Tang Dynasty Postal Relay Station System

Timeline

1. 701–741Relay roads of the two capitals · Central PlainsTang relay stations were divided into water, land, and combined types, managed by station masters and station workers who tended horses and boats; the Tang Six Codes recorded that the Court of Imperial Stud managed relay horses and the Ministry of War's Bureau of Carriages oversaw relay transmission; during the Kaiyuan era there were thousands of relay stations nationwide, delivering documents hundreds of li per day.
2. 755–763Hebei–Central Plains relay road · North ChinaDuring the war, relay horses were largely requisitioned by military commands, relay stations were damaged, and courier posts interrupted; the court relied on urgent relay transmission to coordinate loyalist troops and military reports, transforming the relay system from an everyday administrative facility into a wartime military communications lifeline.
3. 764–800Relay roads of Tang circuits, prefectures, and counties · ChinaAfter the rebellion, the court's finances were strained, relay horses were reduced and stations merged or abolished; regional commands often seized relay horses and dispatch rights, creating a dual relay system between the center and the military commissioners. Although efforts were made to restore it during the Zhenyuan era, relay efficiency never matched the Kaiyuan heyday.