Was there something about the opium war?

Yes, the Opium Wars were a series of conflicts between China and Western powers, primarily Britain, in the 19th century.

The First Opium War (1839-1842) was sparked by tensions between China and Britain over trade imbalances, particularly the trade of opium from British India to China. The Chinese government, alarmed by the social and economic impact of widespread opium addiction, attempted to halt the opium trade leading to a confrontation with Britain.

The conflict resulted in a decisive victory for the British, primarily due to their superior military technology. The Treaty of Nanking (1842) marked the end of the First Opium War. China was forced to cede Hong Kong to Britain, open five treaty ports for trade, pay reparations and grant extraterritorial rights to British citizens.

The Second Opium War (1856-1860) erupted due to renewed tensions between China and Western powers, including Britain and France over trade missionary activities and issues of sovereignty. The conflict culminated in the signing of the Treaty of Tientsin (1858) and the Convention of Peking (1860). These agreements further opened China to foreign trade, expanded access to treaty ports, granted more extraterritorial rights to Western powers, and imposed indemnities on China.

The Opium Wars had significant and detrimental effects on China, leading to increased foreign influence, economic exploitation, and the loss of territorial sovereignty. They also marked the beginning of a period of Chinese history known as the "Century of Humiliation," during which China faced extensive external pressures and internal upheavals due to foreign intervention and imperialism.