Gia Long - Unification of Vietnam

Unification of Vietnam

In 1792, the middle and the most notable of the three Tay Son brothers, Nguyen Hue Quang Trung, who had gained recognition as Emperor of Vietnam by driving the Le Dynasty and China out of northern Vietnam, died suddenly. Nguyen Anh took advantage of the situation and attacked northwards. By now, the majority of the original French soldiers, whose number peaked at less than 80 by some estimates, had departed. The majority of the fighting occurred in and around the coastal towns of Nha Trang in central Vietnam and Qui Nhon further to the south in Binh Dinh Province, the birthplace and stronghold of the Tay Son. Nguyen Anh began by deploying his expanded and modernised naval fleet in raids against coastal Tay Son territory. His fleet left Saigon and sailed northward on an annual basis during June and July, carried by southwesterly winds. The naval offensives were reinforced by infantry campaigns. His fleet would then return south when the monsoon ended, on the back of northeasterly winds. The large European wind-powered vessels gave the Nguyen navy a commanding artillery advantage, as they has a superior range to the Tay Son cannons on the coast. Combined with traditional galleys and a crew that was highly regarded for its discipline, skill and bravery, the European-style vessels in the Nguyen fleet inflicted hundreds of losses against the Tay Son in 1792 and 1793.

In 1794, after a successful campaign in the Nha Trang region, Nguyen Anh ordered de Puymanel to build a citadel at Duyen Khanh, near the city, instead of retreating south with the seasonal northeasterly breeze. A Nguyen garrison was established there under the command of Nguyen Anh's eldest son and heir, Nguyen Phuc Canh, assisted by Pigneau and de Puymanel. The Tay Son laid siege to Duyen Khanh in May 1794, but Nguyen forces were able to keep them out. Shortly after the siege ended, reinforcements arrived from Saigon and offensive operations against the Tay Son duly resumed. The campaign was the first time that the Nguyen were able to operate in Tay Son heartland during an unfavorable season. The defensive success of the citadel was a powerful psychological victory for the Nguyen, demonstrating their ability to penetrate Tay Son territory at all times of year. The Nguyen then proceeded to slowly erode the Tay Son heartland.

Heavy fighting occurred at the fortress of Qui Nhon, until it was captured in 1799 by Nguyen Canh's forces. However, the city was quickly lost and was not regained until 1801. The superior firepower of the improved navy played the decisive role in the ultimate recapture of the city, supporting a large overland attack. After the capture of their stronghold at Qui Nhon, the Tay Son, led by Quang Trung's son Quang Toan, came quickly. In June, the central city of Hue—the former capital of the Nguyen—fell and Nguyen Anh crowned himself emperor, under the reign name Gia Long, which was derived from Gia Định (Saigon) and Thăng Long (Hanoi) to symbolize the unification of north and south Vietnam. He then quickly overran the north, with Hanoi captured on 22 July 1802. After a quarter-century of continuous fighting, Gia Long had unified what is now modern Vietnam, and elevated his family to a position never previously occupied by Vietnamese royalty. Vietnam had never before occupied a larger landmass. Gia Long became the first Vietnamese ruler to reign over territory stretching from China in the north, all the way to the Gulf of Siam and the Ca Mau peninsula in the south. Gia Long's then petitioned the Qing Dynasty of China for official recognition, which was promptly granted. The French failure to honour the treaty signed by Pigneau meant Vietnam was not bound to cede the territory and trading rights that they had promised.