Bloody Road to the Sui Dynasty
Rule by monarchy had been a misfortune for China, with war and bloodshed often the means of working out successions to power. Competent rulers eventually had been followed by the incompetent, with corruption of governmental processes and neglect of the interests of common people. Had those in power been dependent upon the will of the common people they might have done more for the common people -- including more storage of grain in years of good harvests to cover times of disaster.
Incompetent government and upheaval made China vulnerable to invasion. In the 400s China again was unable to defend its borders. Xiongnu armies came from the north, and Xiongnu chieftains divided northern China among themselves. By the year 500 one dynasty of Xiongnu kings, the Tuoba Wei, dominated the whole of northern China, and culturally they were becoming more Chinese. In the south, meanwhile, a recent string of Chinese families had risen and fallen from power while engaging in rampages of murder as a way of settling disputes over who was to rule.
In northern China, power within the Tuoba Wei family passed to a dowager queen who was a devout Buddhist. This was Queen Hu. She struck against all who displeased her. She executed lovers who had displeased her. She forced a rival into a convent and had her executed, and in 528 she executed her son, who had been growing restless under the tutelage of her lovers. Outraged officials rebelled. Queen Hu cut her hair and sought refuge in a Buddhist nunnery, but the officials dragged her out and murdered her.
In 577 CE, another Xiongnu chieftain unified the north by force of arms, and in 580 this ruler died under suspicious circumstances. His son-in-law, the Duke of Sui, a tough Buddhist soldier from an aristocratic Chinese family, took power. He proclaimed that heaven and earthly signs indicated that those who had been ruling in the north had lost the mandate of heaven and that he, being virtuous and wise, had been designated by heaven as the rightful successor. He took the name Emperor Wen (Wen-di), and he had fifty-nine murdered to eliminate rivalry.
The Chinese of northern China had absorbed the Xiongnu invaders, and northern China remained a mix of peoples like much of the rest of the civilized world. And after consolidating his power in northern China he conquered the southern half of China. China was united again. And with Emperor Wen having the family name of Sui, his dynasty became known as the Sui.
The Sui Dynasty began when Wendi's daughter became the Empress Dowager of Northern Zhou, with her stepson as the new emperor. After crushing an army mutiny in the eastern provinces as the prime minister of Zhou, Wendi took the throne by force and claimed himself to be emperor. In a bloody purge, Wendi had fifty-nine princes of the Zhou royal family eliminated, yet nonetheless was known as the 'Cultured Emperor' (581 - 604 CE). He abolished the anti-Han policies of Zhou and reclaimed his Han surname of Yang. Having won the support of the Confucian scholars that had powered previous Han dynasties (abandoning the nepotism and corruption of the nine-rank system), Wendi initiated a series of reforms aimed at strengthening his empire for the war that would reunify China.
In his campaign for southern conquest, Wendi assembled thousands of boats to confront the naval forces of the Chen Dynasty on the Yangtze River. The largest of these ships were very tall, having five layered decks, the capacity of holding 800 passengers, and were outfitted with six 50-foot-long booms that were used to swing and damage enemy ships, or to pin them down so that Sui marine troops could use grapple-and-board techniques. Besides employing Xianbei and Chinese ethnicities for the fight against Chen, Wendi also employed the service of aborigines from southeastern Sichuan, peoples that Sui had recently conquered.
In 588 CE, the Sui had amassed 518,000 troops along the northern bank of the Yangtze River, stretching from Sichuan to the Pacific Ocean. The Chen Dynasty was meanwhile collapsing, and could not withstand such an assault. By 589 CE, Sui troops entered Jiankang (Nanjing) and the last emperor of the southern Chen dynasty surrendered. The city was razed to the ground, while Sui troops escorted Chen nobles back north, where the northern aristocrats became fascinated with everything the south had to provide culturally and intellectually.
Although Wendi was famous for bankrupting the state treasury with warfare and construction projects, he made many improvements to infrastructure during his early reign. He established granaries as sources of food and as a means to regulate market prices from the taxation of crops, much like the earlier Han Dynasty.