The First Tet Offensive of 1789

In January 1789 the Vietnamese defeated a Chinese army and drove it from Vietnam. What might be called the first Tet Offensive is regarded as the greatest military achievement in modern Vietnamese history. Just as the 1904 Japanese strike on Port Arthur foreshadowed their 1941 attack on Pearl Harbor, this 1789 offensive should have been a lesson for the United States that Tet had not always been observed peacefully in Vietnam.

Strangely, the 1789 victory goes largely unmentioned in Western histories of Vietnam. For example, Joseph Buttinger in The Smaller Dragon: A Political History of Vietnam devotes less than a sentence to the offensive, and Stanley Karnow in Vietnam, A History does not mention it at all.

In the mid-18th century Vietnam was divided in two, approximately along what became the DMZ of the 16th parallel during the Vietnam War. The Trinh lords ruled the north and the Nguyen family held sway in the south. Each family hated the other and ruled in the name of the powerless Le king at Thang Long (present-day Hanoi).

Widespread corruption throughout Vietnam led to increased demands on the population for tribute and also to peasant uprisings, the most important being the Tay Son Rebellion against the Nguyen in the south. That rebellion was led by three brothers, named (coincidentally) Nguyen Nhac, Nguyen Lu and Nguyen Hue, from the village of Tay Son in present-day Binh Dinh province. The Tay Son, as the brothers and their followers came to be known, advocated seizing property from the rich and distributing it to the poor. They also attracted support from powerful Chinese merchants who opposed restrictive trade practices. The rebellion thus began with peasants and merchants opposing mandarins and large landowners.

The Tay Son built an army in the An Khe Highlands in western Binh Dinh province. The area was strategically important, and there they drew support from disaffected minorities. The brothers were also aided by the fact that the youngest of them, Nguyen Hue, turned out to be a military genius.

In mid-1773, after two years of careful preparations, a Tay Son army of some 10,000 men took the field against the Nguyen. Soon the Tay Son had seized the fort of Qui Nhon; they next took the provinces of Quang Ngai and Quang Nam, and by the end of the year they seemed poised to overthrow the ruling Nguyen family altogether. At this point, however, in 1775, a Trinh army moved south in the name of the Le dynasty and took Phu Xuan (present-day Hue). The Trinh defeated the Tay Son in battle and announced they would stay in the south to put down the rebellion. The Tay Son managed to survive only by reaching accommodation with the Trinh, until the latter tired of their southern involvement and withdrew into the north.

The Tay Son were then again free to concentrate on the Nguyen, although it took the rebels 10 more years to defeat them. In 1776 they attacked the Nguyen stronghold of Gia Dinh province and took Sai Con (later Saigon and present-day Ho Chi Minh City). Only one Nguyen prince, Nguyen Anh, escaped; he and a few supporters fled into the swamps of the western Mekong Delta. Having now defeated the Nguyen, in 1778 Nguyen Nhac proclaimed himself king, with his capital at Do Ban in Binh Dinh province.

Later Nguyen Anh mounted a counterattack, recapturing Gia Dinh and Binh Thuan provinces. In 1783, Tay Son troops led by Nguyen Hue again defeated Nguyen Anh and forced him into refuge on Phu Quoc Island, whereupon a desperate Nguyen Anh called in the Siamese. In 1784, Siam (present-day Thailand) sent between 20,000 and 50,000 men and 300 ships into the western Mekong Delta. Harsh Siamese occupation policies, however, caused many Vietnamese to rally to the Tay Son.