(1787, 1874, and 1884). The Treaty of 1787 on Offensive and Defensive Alliance was signed at Versailles on November 28 of that year. It was the first treaty to be concluded governing Vietnamese-French relations and was used by France to consolidate its influence in Vietnam. Under the treaty the king of France undertook to give military assistance to Prince Nguyen Anh, who had been removed from power during the national uprising of the Tay Son rebels (1771-1802). In return Nguyen Anh was to give the French crown full possession of the island of Poulo Condore and the island forming the bay of Da Nang, the main port of southern Vietnam. France was also accorded exclusive commercial and political privileges throughout the entire territory of southern Vietnam. The French Revolution, how-ever, which began in 1789, prevented France from realizing her aggressive designs in Vietnam. In 1857 the French them-selves acknowledged as invalid the Vietnamese-French Treaty of 1787.
The Treaty of 1874 on Peace and Alliance was signed in Saigon on March 15, and the instruments of ratification were exchanged in Hue on Aug. 26, 1875. The treaty of 1874 officially replaced the Vietnamese-French-Spanish Treaty of 1862. By this treaty France’s right of possession of the whole territory of southern Vietnam was recognized, including the three western provinces annexed in 1867. Vietnam pledged to coordinate its foreign policy with French policy and renounced the right to conclude any trade agreements without first informing France. Vietnam opened to trade the ports of Qui Nhon in Binh Dinh Province, Haiphong, and the town of Hanoi, as well as the entire Hong Ha (Red River), from its mouth to the Chinese province of Yünnan.
The Protectorate Treaty of 1884 was concluded at Hue on June 6, and instruments of ratification were exchanged there on Feb. 23, 1886. By this treaty the second French-Vietnamese War of 1883-84 came to an end, and as a result Vietnam was completely subjugated by the French colonialists. According to Article 1 of the treaty, Vietnam—with the exception of the southern part of the country, Cochin China, which had been conquered earlier and had been as-signed the status of a colony—recognized the French protectorate. France was accorded the right to maintain armed forces in the forts of Thuenan. According to Article 2 all other Vietnamese fortifications on the Hue River, situated along the approaches to the capital, were to be razed to the ground. The other 17 articles of the treaty established the terms of the French protectorate, which in effect meant the transformation of Vietnam into a French colony.