<P> 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 . </P> <P> 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 . </P> <P> The dynasty is often compared to the earlier Qin dynasty for unifying China after prolonged division . Wide - ranging reforms and construction projects were undertaken to consolidate the newly unified state, with long - lasting influences beyond their short dynastic reigns . </P> <P> Towards the late Northern and Southern dynasties, the Northern Zhou conquered the Northern Qi in 577 and reunified northern China, The century trend of gradual conquest of the southern dynasties of the Han Chinese by the northern dynasties, which were ruled by ethnic minority Xianbei, would become inevitable . By this time, the later founder of the Sui dynasty, Yang Jian, an ethnic Han Chinese, became the regent to the Northern Zhou court . His daughter was the Empress Dowager, and her stepson, Emperor Jing of Northern Zhou, was a child . After crushing an army in the eastern provinces, Yang Jian usurped the throne to become Emperor Wen of Sui . While formerly the Duke of Sui (隨) when serving at the Zhou court, where the character "Sui (隨)" literally means "to follow" and implies loyalty, Emperor Wen created the unique character "Sui (隋)", morphed from the character of his former title, as the name of his newly founded dynasty . In a bloody purge, he had fifty - nine princes of the Zhou royal family eliminated, yet nevertheless became known as the "Cultured Emperor". Emperor Wen abolished the anti-Han policies of Zhou and reclaimed his Han surname of Yang . Having won the support of Confucian scholars who held power in previous Han dynasties (abandoning the nepotism and corruption of the nine - rank system), Emperor Wen initiated a series of reforms aimed at strengthening his empire for the wars that would reunify China . </P>

Long term cause of the sui dynasty reunites china