Trịnh–Nguyễn Conflict in Vietnam

Timeline

1. 1590–1593Thăng Long · VietnamUnder Trịnh Tráng, the Later Lê dynasty largely eliminated Mạc remnants, but the Lê emperor became a puppet. Trịnh Tráng, styling himself a restorer of the dynasty, held real military and political power in the north, forming a dual power structure with Nguyễn Hoàng garrisoned in the south.
2. 1593–1597Huế · VietnamNguyễn Hoàng built his power base in Huế, controlling Quảng Nam and Huế and developing military-agricultural colonies and foreign trade. Trịnh Tráng consolidated the tax system of the Red River Delta; the two sides used the Nghệ An–Quảng Bình line as a boundary, nominally remaining loyal to the Lê dynasty while each ruling independently.
3. 1597–1600Nghệ An–Quảng Bình border · VietnamIn the late 1590s, the Trịnh and Nguyễn garrisoned troops along the border and competed for taxes and talent, with relations growing increasingly tense. Though full-scale civil war had not yet broken out, the north–south division had become irreversible, setting the stage for the formal split along the Giao Thủy River (Kiên Giang) in the 1620s.