Trịnh Tùng
In 1592, when Trịnh Tùng laid siege to the Eastern Capital (modern-day Hanoi), Nguyễn Hoàng lend him resources and troops. The Nguyen army joined the Royal (Trịnh) army and helped destroy the remainder of the Mac army. For reasons that are mysterious, when the new Emperor, Lê Kinh Tông, ascended the throne, Nguyễn Hoàng refused to recognize the new sovereign and instead took for himself the new title of "Good Prince" (Huu Vuong) in 1600. Perhaps an explanation is found in that his nephew Trịnh Tùng had been given a similar title just one year earlier: "Pacifying Prince" (Binh An Vuong). Nguyễn Hoàng had many children (10 sons) but most of them either lost their lives in the battlefields or stayed in the North. His 6th son Nguyễn Phúc Nguyên succeeded him upon his death in 1613. He ruled the south for 55 years.