Đàng Trong
Both the leaders of the Trịnh and clans, who de facto ruled the two-polities kingdom from the 16th to the 18th century, used the title "Chúa" (lord), which is outside of the classical hierarchy of nobility. After ousted the Mac in 1592, the two Thanh Hoa clans divided the kingdom into two simultaneously coexist but rival militarist regimes: the northern Đàng Ngoài or Tonkin ruled by the Trịnh family while the southern Đàng Trong or Cochinchina ruled by the Nguyen family; their natural border is the city of Đồng Hới (18th parallel north). Each polity had its own independent government, however, they still sought to subordinate with the Royal House of Le, which also remained under Trịnh supervision.