9 October 1911, Hankou on the Yangtze. A bomb being built for a revolution goes off by accident, and the police find the membership lists. The next night soldiers across the river in Wuchang, whose names are on them, rise rather than wait for arrest. Within weeks province after province leaves the Qing. The emperor, Puyi, is five.
Why then
The Qing have been losing for seventy years: the Opium Wars, Japan in 1895, the eight foreign armies that took Beijing after the Boxer rising of 1900. Their own late reforms trained the officers who now want them gone, and a quarrel over railway loans already has Sichuan in revolt.
What they wanted
The soldiers want to survive the night. Provincial gentry want the railways and taxes in their own hands. Sun Yat-sen, the best-known revolutionary, reads the news in a Denver newspaper. Yuan Shikai, the general the court recalls to save it, is after the throne's power, and later the throne.
What changed
Puyi abdicates in February 1912. Two thousand years of emperors end, and the republic soon falls to Yuan, then to the warlords. Nationalists and Communists will spend forty years fighting over who rebuilds China.
Still argued
Revolution or collapse? The old story credits Sun and his revolutionaries; most historians now give more weight to the provinces, the army and the dynasty's own reforms.