Sui reunited China in decades—then Goguryeo broke it
From 581 to 618 the Sui dynasty ended centuries of north–south split, dug the Grand Canal, and rebuilt walls and Luoyang. Failed wars on Goguryeo and ruinous projects sparked revolts; Emperor Yang was murdered in 618 after only thirty-seven years of Sui rule.
After the Xianbei-led Northern Zhou conquered Northern Qi in 577, its regent Yang Jian, a northwestern military aristocrat, took power as Emperor Wen. The family claimed descent from the Han official Yang Zhen and even from Zhou kings. The capital Daxing (Chang’an) later yielded to a refounded Luoyang in 605. In 588 some 518,000 troops lined the Yangtze, including five-deck warships carrying 800 passengers besides crew, and by 589 the Chen capital Jiankang had fallen.
Because Daxing sat far from the rich east and south, Wen began the Grand Canal, and branches later ran toward Jiangdu and Yuhang. He extended the Great Wall and stocked granaries that fed people and steadied grain prices, though his wars and works drained the treasury. His diplomacy split the Turkic Khaganate into eastern and western halves. Word of these events reached Byzantium, where writers began calling China Taugast, a name learned from Central Asian Turks.
Emperor Yang took the throne in 604, possibly by murdering his father, and restored Confucian schooling and examinations for officials. Both Sui rulers campaigned in Vietnam: the Hanoi area was retaken from Lý Phật Tử in 602, and when Champa’s war elephants attacked farther south, Sui troops feigned retreat and trapped them in dug pits.
Korea proved fatal. The army raised against Goguryeo was so vast that its columns reportedly took 30 days to leave their last camp near Shanhaiguan, yet repeated invasions through 614 failed. Popular fury over losses and labour levies spread into revolt, and Yuwen Huaji’s men killed Emperor Yang in 618, after just 37 years of Sui rule.
Source: Sui dynasty
