Portrait painting of duke Trịnh Cối.
|Reign||1570 - 1572|
Sáo Sơn village, Vĩnh Hùng commune, Vĩnh Lộc district, Thanh Hoa town, Annam
Đông Kinh, Annam
|Spouse||Lại Thị Ngọc Nho|
|Mother||Lại Thị Ngọc Vi|
Trịnh Cối was born in 1584 at Sáo Sơn village, Vĩnh Hùng commune, Vĩnh Lộc district, Thanh Hoa town (now Thanh Hóa province). He was the eldest son of duke Trịnh Kiểm and had a title Marquis Tuấn Đức (俊德侯).
February 1570, Trịnh Kiểm has died, so emperor Lê Anh Tông gave Trịnh Cối the authority with new title Duke Đạt Nghĩa (義達公). However, some officials and generals didn't comply with Trịnh Cối, so they supported his younger brother Trịnh Tùng. April 1570, officials Lê Cập Đệ, Trịnh Vĩnh Thiệu, Trịnh Bách, Phan Công Tích with their inferiors went to Trịnh Tùng's house and advice him to proceed a coup d'état. At first Trịnh Tùng pretened refusing for the surveying, then he agreed completely.
After when Northern dynasty hearded of the news about a confusion in Thanh Hoa, emperor Mạc Mục Tông has assigned prince Mạc Kính Điển in the lead 100,000 soldiers with 700 warships to attack Southern dynasty. August 1570, all of Thanh Hoa produced a stir.
Mạc forces came on waterfronts Linh Tràng, Chi Long, Hội Triều and occupied Bút Cương village easily'n quickly. Northern dynasty garrisoned in Hà Trung, both parties faced about 10 miles. So Trịnh Cối had stucked between Mạc forces and Trịnh Tùng, he was reluctant to surrender Mạc Kính Điển.
Mmediately Mạc forces cancelled marching orders, so Trịnh Cối directed his mother, wives, children and inferiors about 1,000 persons to follow marshal Mạc Kính Điển in the backing Đông Kinh. Emperor Mạc Mục Tông has conferred him a title Marquis Trung Lương (中良侯) and his some inferiors titles "duke". All of them had been banished in the capital.
A surrender made Trịnh Cối to be slighted by Lê dynasty's records, Trịnh clan annals hasn't even recognize him as the leader of Southern dynasty. He was only recognized by Nguyễn dynasty's records. However, contemporary lord Trịnh Tráng (son of lord Trịnh Tùng) still conferred a posthumous title Archduke Trung Lương (忠國公).