The Trịnh forces quickly overran the Nguyễn capital in 1774, while the Nguyễn lords fled south to Saigon. The Nguyễn fought against both the Trịnh army and the Tây Sơn, but their effort was in vain. By 1777, Gia Định was captured and nearly the entire Nguyễn family was killed except one nephew, Nguyễn Ánh, who managed to flee to Siam.
In 1774, the Trịnh forces swiftly captured the Nguyễn stronghold, forcing the Nguyễn lords to flee south to Saigon. The Nguyễn fought against both the Trịnh army and the Tây Sơn, but their efforts were ultimately unsuccessful. By 1777, Gia Định fell, and most of the Nguyễn family was killed, leaving only one nephew, Nguyễn Ánh, who escaped to Siam.