Treaty of Nanking
The Treaty of Nanking in 1842 concluded the Opium War. It awarded Great Britain a large indemnity from the Qing Dynasty in China and denied the Qing government tariff control over some of its own borders. Furthermore, it opened additional ports to Great Britain and ceded the island of Hong Kong to the British as well.
The Earth and Its Peoples A Global History, Bulliet et al., 2005.