After the fall of the Han Dynasty in 220 AD, China was plunged into a period of disunity that lasted over three hundred years; it was the longest period of disunion in Chinese history.  This period of Chinese disunity is known as the Six Dynasties period due to the six dynasties that ruled China between 220 AD and 589 AD. The period is usually broken into three sections: the Three Kingdoms (220-280 AD), Jin Dynasty (265-420 AD), and Southern and Northern Dynasties (420-589 AD). By 577 AD, China was divided into two dynasties: The Northern Zhou and the Southern Chen. The leader of the Northern Zhou, Zhou Wu, had ambitions to reunite all of China under his throne, something that had not been accomplished since the days of the Jin Dynasty two centuries before. He was a young and ambitious ruler, but just as he was planning the conquest he grew ill and died while campaigning at the age of thirty-five.  The task of reuniting China would fall to one of his officials named Yang Jian, a man who had fought for him, had given his daughter to be the crown prince’s wife, and had received the noble title “Duke of Sui” for his services. Yang Jian had also helped the crown prince, his son-in-law, Zhou Xuan, ascend to the imperial throne in 578 AD. Zhou Xuan was nineteen when he became emperor of Northern Zhou, and sadly possessed none of his father’s ambitions for long-lasting glory. He was more interested in his current power, referring to himself as “The Heaven,” while referring to his nobles of the court as “the earth.” He committed many gross offences and abused his power: he forced all of his officials to give up any decorative clothing or ornaments so that his would stand out; he grew paranoid and executed anyone who offended him; he went on long, lavish parades through the countryside to show off his power, while leaving his father-in-law Yang Jian in charge.  It was only a year after his coronation that he made his six-year-old son emperor in name, desiring to give himself more freedom to indulge himself in his carnal desires, such as beating and raping the women of the court.  Fortune favored the northern dynasty, the wayward emperor had a stroke and died in 579 AD, at the young age of twenty. Yang Jian, desiring to protect the empire of his old friend, took immediate action by forging a document making him regent for the new emperor, his seven-year-old grandson, Zhou Jing.
Among Yang Jian’s most notable supporters were the great general Gao Ying and a famous writer named Li Delin. Gao Ying used his influence to wipe out any opposition to his regency, while Li Delin wrote beautifully convincing political rhetoric about Yang Jian’s right to rule. By 580, the young emperor had signed an imperial edict praising Yang Jian’s worthiness. The edict proclaimed him “Supreme Pillar of State, Grand State Minister, responsive to the mountains and rivers, answering to the emanations of the stars and planets. His moral force elevates both the refined and the vulgar, his virtue brings together what is hidden and what is manifest, and harmonizes Heaven and Earth.” In December of that year, Yang Jian made himself a prince, higher in rank than any other noble in the court. In January of 581, an edict of abdication appeared, clearly the writing of Li Delin but with emperor Zhou Jin’s signature at the bottom. As was Chinese custom, Yang Jian refused three times to take the title, though he was eventually “persuaded” to ascend to the imperial throne as Sui Wendi, emperor of the north  The new emperor, assured that he had received the Mandate of Heaven, made sure that his ascension would be unchallenged by murdering fifty-nine members of the Northern Zhou family, including his own grandson. When the king of the southern Chen dynasty died in 582, leaving behind a weak heir, the new emperor saw his chance to reunite China.
The Sui emperor spent seven years carefully planning his tactics. He first used rhetoric by sending agents into the south with three hundred copies of a manifesto that listed all the faults of the new southern emperor, explaining that the emperor’s vice and sin had deprived the southern dynasty of the Mandate of Heaven  The Mandate of Heaven was an ancient Chinese philosophical concept whose roots can be traced back to the Zhou Dynasty. The concept teaches that Heaven would bless the authority of a just ruler as defined by Confucian principles, but would be displeased with despotic, corrupt rulers and would overthrow them. The Mandate of Heaven would then transfer to those who would rule best.  The actual war began in 582, and soon Sui forces marched on the southern capital of Nanjing; by the time they arrived at the city walls, the power of the Southern Chen had crumbled. The Sui armies took control of the city with remarkable ease. Sui Wendi had united China using a two-pronged strategy of rhetoric and military force.
The Sui emperor put into place a series of swift and effective reforms. He restricted the use of weapons to the army, insuring that the possibility of rebellion and bloody feuds among the people would be reduced drastically. He ordered that the Great Wall to be rebuilt where it had crumbled. He then reorganized the governments of the north and south into one tidy, efficient unit that was highly structured and hierarchical, with each office having its own set of privileges, rank, and uniforms.  The emperor also ordered a new set of laws that would apply across the entire empire, replacing the contradictory and disorganized mass of local regulations in place at the time. He even married his son and heir, Yangdi, to a southern bride to reduce southern hostility to northern takeover. All later Chinese dynasties were indebted to the Sui’s accomplishments, especially the Tang Dynasty which built upon the foundation of the Sui and came to dominate culture and politics in all of East Asia for nearly three hundred years.
.Denis C. Twitchett, ed., The Cambridge History of China, vol. 3, Sui and T’ang China, 589-906 Ad, Part 1 (Cambridge: Cambridge University Press, 1979), 48.
. Susan Wise Bauer, The History of the Medieval World: from the Conversion of Constantine to the First Crusade (New York: W. W. Norton & Company, 2010), 226.
. Ibid., 226
.Richard Bulliet et al., The Earth and Its Peoples, Brief Edition, Volume I, 5 ed. (Boston: Cengage Learning, 2011), 40.