Lý Nhân Tông
Emperor Lý Nhân Tông was the longest reigned ruler in the history of Vietnam. As he was childless, #his nephew Lý Dương Hoán (李陽煥), who he adopted, was chosen to be the crown prince. Lý Nhân Tông died in 1128. Lý Dương Hoán was enthroned at age 11 and took temple name Lý Thần Tông. The death of Lý Nhân Tông had marked the transition of succession from the main line to the cadet line. Lý Thần Tông would die young after ruling for 10 years. Crown prince Lý Thiên Tộ then enthroned as Emperor Lý Anh Tông at 3 year old.