1642 Kaifeng Flood

Kaifeng, a prefecture-level city in eastern Henan province, People's Republic of China, located along the southern bank of the Yellow River, was flooded in 1642 by the Ming Dynasty army with water from the Yellow River to prevent the peasant rebel Li Zicheng from taking over. Roughly half of the 600,000 residents of Kaifeng were killed by the flood and the ensuing peripheral disasters such as famine and plague, making it one of the deadliest single acts of war in history (excluding systematic genocide) and the second greatest single loss of human life of its time.

The flood is sometimes referred to as a natural disaster due to the role of the Huang He river and is currently listed as the 7th deadliest natural disaster in history with a death toll of some 300,000.

The city was once the capital of China, but it did not experience the same population growth as its surrounding provinces and after this disaster the city was abandoned until 1662 when it was rebuilt under the rule of the celebrated Qing emperor Kangxi. It remained a rural backwater city of diminished importance thereafter and experienced several other less devastating floods.

The flood brought an end to the "golden age" of the Jewish settlement of China, which is said to span from about 1300 to 1642. By the time of the flood the Jewish population of China had reached about 5,000, mostly in Kaifeng.