The Sui dynasty, which lasted 29 years and witnessed the reigns of three emperors, played a role more important than its length of existence would suggest. The Sui reunited China together again under the leadership of Emperor Wen of Sui and set up many institutions that were to be adopted by their successors, the Tang. These included the government system of Three Departments and Six Ministries, standard coinage, improved defense and expansion of the Great Wall, and official support for Buddhism.
The Sui unified the Northern and Southern dynasties and reinstalled the rule of ethnic Han Chinese in the entire China proper, along with sinicization of former nomadic ethnic minorities within its territory. It was succeeded by the Tang dynasty, which largely inherited its foundation.
Founded by Emperor Wen of Sui, the Sui dynasty capital was Chang’an (which was renamed Daxing, 581–605) and later Luoyang (605–614). Emperors Wen and Yang undertook various centralized reforms, most notably the equal-field system, intended to reduce economic inequality and improve agricultural productivity; the institution of the Three Departments and Six Ministries system; and the standardization and re-unification of the coinage. They also spread and encouraged Buddhism throughout the empire. By the middle of the dynasty, the newly unified empire entered a golden age of prosperity with vast agricultural surplus that supported rapid population growth.
A lasting legacy of the Sui dynasty was the Grand Canal. With the eastern capital Luoyang at the center of the network, it linked the west-lying capital Chang’an to the economic and agricultural centers of the east towards Hangzhou, and to the northern border near modern Beijing. While the pressing initial motives were for shipment of grains to the capital, and for transporting troops and military logistics, the reliable inland shipment links would facilitate domestic trades, flow of people and cultural exchange for centuries, Along with the extension of the Great Wall, and the construction of the eastern capital city of Luoyang, these mega projects, led by an efficient centralized bureaucracy, would amass millions of conscripted workers from the large population base, at heavy cost of human lives.
After a series of costly and disastrous military campaigns against Goguryeo, one of the Three Kingdoms of Korea, ended in defeat by 614, the dynasty disintegrated under a series of popular revolts culminating in the assassination of Emperor Yang by his ministers in 618. The dynasty, which lasted only thirty-seven years, was undermined by ambitious wars and construction projects, which overstretched its resources. Particularly, under Emperor Yang, heavy taxation and compulsory labor duties would eventually induce widespread revolts and brief civil war following the fall of the dynasty.
Just like the Qin, the Sui overused their resources and collapsed in just a short period of its existence, and the next subsequent Chinese dynasty ushered in another golden age in China’s history.