sentences:  In 1789, Tánh forced the Tây Sơn general Pham Van Tham, who was the general-in-chief of the Tây Sơn garrison in southern Vietnam, to surrender to the Nguyễn army, which marked the end of Tây Sơn rule in Gia Định.Later in 1790, Võ Tánh led an army that captured the citadel of Diên Khánh.In 1793, Nguyễn Ánh launched the first expedition to Quy Nhơn.