Destruction of opium at Humen

The destruction of opium at Humen began on 3 June 1839, lasted for 23 days, and involved the destruction of 1,000 long tons (1,016 t) of illegal opium seized from British traders under the aegis of Lin Zexu, an Imperial Commissioner of Qing China. Conducted on the banks of the Pearl River outside Humen Town, Dongguan, China, the action provided casus belli for Great Britain to declare war on Qing China.

Source: Wikipedia — Destruction of opium at Humen (CC BY-SA 4.0)