After the Tang dynasty conquered Goguryeo in 668, the Protectorate General to Pacify the East, otherwise known as the Andong Protectorate, was created in Pyongyang and supposedly stationed with 200,000 soldiers. The protectorate was divided into 9 commanderies, 42 prefectures, and 100 counties. In 669 the people of Goguryeo revolted in response to Tang governance. In response the Tang forcibly deported 78,000 households and resettled them in empty areas south of the Changjiang and Huai River, each in contemporary China. The weak and poor were left behind and assigned to guard duty in service of the protectorate. From 670 to 673 the rebels launched an uprising every year, the last of which lasted for four years. The Goguryeo loyalists were aided by the kingdom of Silla, who were angered by Emperor Gaozong of Tang. Originally Emperor Taizong of Tang promised to exchange Baekje and the lands south of Peonyangin return for Silla's military cooperation. However Taizong died before the conquest of Goguryeo was completed, and his successor Gaozong reneged on the promise. In 675 the Tang attacked Silla and defeated them in Gyeonggi. In response Munmu of Silla dispatched a tributary mission to Tang with apologies. Gaozong accepted Munmu's apologies and withdrew Tang troops to deal with the Tibetan threat in the west. Seeing the Tang's strategic weakness, Silla renewed the advance on Tang territory. By 676 the Tang were forced to retreat and relocate the protectorate seat to the more easily defendable city ofLiaoyang. In 677 the seat was moved to Xincheng, in modern Fushun, Liaoning. In 667 the deposed Bojang of Goguryeo was designated "Liaodong Commander King of Joseon". Upon arriving in Liaodong, he plotted with the Mohe people to revive Goguryeo. News of his intentions reached the Tang, and Bojang was banished to southwestern China in 681. In 714, the seat was moved to Pingzhou, in modern Lulong County, Qinhuangdao, Hebei. In 736, the Tang formally recognized Silla's control of Korea south of the Taedong River. In 743, the seat was moved to the Old City of Liaoxi, possibly Ying Prefecture. The Protectorate General to Pacify the East, otherwise known as the Andong Protectorate, was abandoned in 756 or ended in 761.
