The Trịnh lords (Vietnamese: Chúa Trịnh; Chữ Nôm: 主鄭; 1545–1787), formal title Trịnh Viceroy (Vietnamese: Trịnh vương; Hán tự: 鄭王), also known as Trịnh clan or the House of Trịnh, were a noble feudal clan who de facto ruled northern Vietnam during the Later Lê dynasty. The Trịnh lords and their rivals the Nguyễn were both referred to by their subjects as Chúa (lord) and controlled the country while the Later Lê emperors were reduced to only a titular position. The Trịnh lords traced their descent from Trịnh Khả, a friend and advisor to the 15th-century Vietnamese Emperor Lê Lợi. The Trịnh clan produced 12 lords that dominated the royal court of Later Lê dynasty and ruled northern Vietnam for more than 2 centuries.