The First Opium War (1839-1842) was fought between the British Empire and the Qing Dynasty of China. It began when China attempted to suppress the illegal opium trade, which was causing widespread addiction and social issues. The British, seeking to protect their trade interests, responded with military force, leading to China's defeat and the signing of the Treaty of Nanking, which ceded Hong Kong to Britain and opened several ports to British trade. The Second Opium War (1856-1860) involved Britain and France against China. Triggered by disputes over trade and diplomatic relations, this conflict resulted in further military confrontations. The war ended with the Treaty of Tientsin and the Convention of Peking, which legalized the opium trade, expanded foreign privileges, and allowed foreign missionaries to operate in China, significantly weakening Qing authority.