What was a result of the opium war?

Opium Wars, two armed conflicts in China in the mid 19th century between the Qing dynasty of China and Western countries resulted in an era of treaties between China and imperalist powers -Great Britain, France, USA, Germany, Japan, etc. The main treaty was the Treaty of Nanking (Nanjing), that established that China had to pay Great Britain an indemnity, cede Hong Kong's territory and set a "fair" tariff. The weakening of Qing dynasty was another consequence, which, at the same time, triggered a revolution in 1911.