1527-1650 CE
From 1527 to 1650 CE, the Viets fractured into north and south while pretending unity — the Mạc usurpation splitting the realm, the restored Lê emperors reduced to puppets while Trịnh lords ruled the north and Nguyễn lords carved their own domain from conquered Cham lands in the south. A century of civil war devastated the heartland even as southern colonization pushed toward the Mekong, building the Vietnam that would emerge from division.