The Second Opium War finally ends at the Convention of Peking with the ratification of the Treaty of Tientsin, an unequal treaty.

The Second Opium War, also known as the Second Anglo-Chinese War or Arrow War, was fought between the United Kingdom and France against the Qing dynasty of China between 1856 and 1860. It was the second major conflict in the Opium Wars, which were fought over the right to import opium to China, and resulted in a second defeat for the Qing and the forced legalisation of the opium trade. It caused many Chinese officials to believe that conflicts with the Western powers were no longer traditional wars, but part of a looming national crisis.

The Convention of Peking or First Convention of Peking is an agreement comprising three distinct unequal treaties concluded between the Qing dynasty of China and Great Britain, France, and the Russian Empire in 1860.

The Treaty of Tientsin, also known as the Treaty of Tianjin, is a collective name for several unequal treaties signed at Tianjin in June 1858. The Qing dynasty, Russian Empire, Second French Empire, United Kingdom, and the United States were the parties involved. These treaties, counted by the Chinese among the unequal treaties, opened more Chinese ports to foreign trade, permitted foreign legations in the Chinese capital Beijing, allowed Christian missionary activity, and effectively legalized the import of opium. They ended the first phase of the Second Opium War, which had begun in 1856 and were ratified by the Emperor of China in the Convention of Peking in 1860, after the end of the war.

The unequal treaties were a series of agreements made between Asian countries—most notably Qing China, Tokugawa Japan and Joseon Korea—and Western countries—most notably the United Kingdom, France, Germany, Austria-Hungary, Italy, the United States and Russia—during the 19th and early 20th centuries. They were often signed following a military defeat suffered by the Asian party, or amid military threats made by the Western party. The terms specified obligations to be borne almost exclusively by the Asian party and included provisions such as the cession of territory, payment of reparations, opening of treaty ports, relinquishment of the right to control tariffs and imports, and granting of extraterritoriality to foreign citizens.