Emperor Yang of Sui

Emperor Yang ordered the construction of the Grand Canal, linking the Yellow River and Yangtze River basins. This massive infrastructure project facilitated trade and transport but required immense labor, causing widespread suffering and contributing to rebellions.

Emperor Yang launched a massive invasion of the Korean kingdom of Goguryeo with over 300,000 troops. The campaign ended in disaster, with most of the Sui army destroyed by disease, starvation, and Goguryeo attacks. This defeat severely weakened the Sui dynasty.

Emperor Yang launched a second invasion of Goguryeo. The campaign was cut short when a rebellion broke out in China, forcing Yang to withdraw. This further drained the dynasty's resources and morale.

Emperor Yang launched a third invasion of Goguryeo. Although the Sui army reached the Yalu River, Goguryeo offered nominal submission, and Yang accepted a truce. This campaign further exhausted the Sui treasury and military.

Emperor Yang was assassinated by his own guards in Jiangdu (modern Yangzhou) during a rebellion. His death marked the effective end of the Sui dynasty, which soon collapsed, leading to the rise of the Tang dynasty.