Military history of the Sui dynasty
Unlike the mass conscription of the Han dynasty, these soldiers were promised tangible rewards such as exemption from taxes and labor for their families.
[2][3] On 4 March 581, Yang Jian deposed Yuwen Chan, and declared himself Emperor of the Sui dynasty.
[6] By the late fall of 588, the Sui dynasty had marshaled three fleets and five armies along the Changjiang, in total some 518,000 men.
They encountered at Wolf Tail's rapids a Chen fleet of 100 Green Dragon ships with support from several thousand men in palisade forts on north and south banks.
Lü Zhongsu fled with his fleet to Yan Island beneath Mount Jingmen, but the Sui sent four Five-Banner ships and chased them down.
The move came as a complete surprise to Chen forces on the southern bank due to a series of deceptions by Heruo Bi involving pretending to rotate soldiers and conducting practice hunts.
Meanwhile, a crack force of 500 men under Han Qinhu slipped across the Changjiang upstream of Jiankang and captured Caishi.
[8] I met the armies that opposed me on the way to Jiankang and not only did I defeat them but I made prisoner one of the very distinguished and brave Chen commanders.
[8] In late 590, a large rebellion occurred at Lake Tai in response to rumors that the Sui government was planning on relocating hundreds of thousands of northerners to the north.
The rebellion was eventually ended when Yang Su persuaded one of the two primary rebel leaders to turn on his colleague and hand him over to the Sui in return for his own life.
[14] In 602, Sui forces under Liu Fang annexed the Kingdom of Vạn Xuân ruled by the Early Lý dynasty.
[13] In 608, Sui forces defeat the Tuyuhun, a people of mixed Xianbei and Qiang descent in modern Qinghai Province.
[15] Emperor Yang of Sui began preparations for a campaign against Goguryeo in 610 when he imposed a new tax on wealthy families to purchase horses for his army.
Three hundred seagoing vessels were constructed in Donglai and 10,000 marines were transferred from the southern river systems to crew them.
According to the History of Sui, the combined 30 armies gathered for the expedition numbered 1,133,800 combat troops, and another two million serving in logistical capacity.
Meanwhile, the Sui fleet under Lai Huer set sail from Donglai and entered the Taedong River, arriving near Pyeongyang by the middle of July.
The defenders feigned flight, luring the invaders past the outer walls into an ambush, and drove them back to their ships with heavy losses.
[17] The fortress of Ryotongseong had not fallen and the siege was taking too long, so Emperor Yang sent nine of the thirty armies ahead with 100 days' supply of grain.
Eventually they were forced to retreat due to lack of provisions, but as the nine armies were crossing the Sa River, a strong attack by Goguryeo inflicted immense casualties on the units remaining on the southern bank.
[18] Your brilliant plans expose reality.Your subtle understandings encompass the worldYou win all the battles; you are invincible.Why not accept victory and end this war?
The new army crossed the Liao River on 21 May and laid siege to Ryotonseong while another column attacked Sinseong (near modern Fushun).
[21] In the summer of 615, Emperor Yang of Sui was surrounded at Yanmen Commandery by Shibi Khan, but managed to escape after machinations at the Göktürk court caused them to retreat.
