[1] Through his reign, Anh Tông was just a nominal emperor of south Đại Việt, with actual governing and military power possessed by the Trịnh, a warrior house from Thanh Hóa.
Grand Chancellor Trịnh Kiểm, who had been the virtual ruler of south Đại Việt since the reign of Lê Trang Tông, decided to select Duy Bang as the new emperor.
Therefore, having become emperor, Lê Anh Tông/Lê Duy Bang had to cooperate with Trịnh Kiểm in conducting the war with the Mạc house in order to unite Vietnam.
With the help of Trịnh Kiểm and capable general, Lê Cập Đệ, emperor Anh Tông achieved several victories against the Mạc forces.
The constant battles between the two imperial houses caused heavy damage to the agricultural economy of Đại Việt.
Anh Tông appointed Kiểm's eldest son, Trịnh Cối as Generalissimo, controlling both the government and army of the Lê realm.
Mac forces landed on Thuận Hóa but were utterly defeated by general Nguyễn Hoàng, Trịnh Tùng's uncle-in-law.
On the Nghệ An front, Lê Anh Tông's forces led by Trịnh Tùng managed to repulse Mạc Kính Điển's army.
[13] Anh Tông abandoned the imperial capital, Vạn Lại (Thanh Hóa) and escaped with his four eldest sons Bách, Lựu, Ngạnh and Tùng to Nghệ An.