The significance of the Treaty of Nanking, signed in 1842, was its role in ending the First Opium War between Britain and China. This unequal treaty forced China to cede Hong Kong to Britain and grant extraterritorial rights to British citizens. It marked the beginning of a series of Unequal Treaties that significantly undermined Chinese sovereignty and opened several ports to foreign trade. The treaty was pivotal in shaping modern Chinese history, leading to resentment towards foreign powers and fostering a sense of nationalism that would later fuel movements against imperialism and for reform.