Natural disasters that redirected world history

Which natural disaster changed history to the greatest extent?

There is no single uncontested choice, but the Gallipoli earthquake, the 1887 Yellow River flood, the Plague of Justinian, and the Black Death are strong candidates because each redirected major states and societies.

The 1354 Gallipoli earthquake is offered because damaged fortifications helped the Ottomans secure a European foothold with consequences for Byzantium and the Renaissance. The 1887 Yellow River flood is another candidate because of its immense death toll, economic disruption, and damage to China's modernization. The Plague of Justinian is linked to the weakened Byzantine and Sasanian empires, while the Black Death transformed European population and institutions. The exchange leaves the ranking open because the historical importance of a disaster depends on the political systems and recovery paths it alters.