Yeon Namsaeng (Korean: 연남생; Hanja: 淵男生; 634–679) was the eldest son of the Goguryeo Dae Magniji [ko] (대막리지, 大莫離支; highest-ranking official or dictator;[1] "prime minister") Yeon Gaesomun (603?
Namgeon and Namsan took advantage of their brother's absence and took control of Pyeongyang and the Royal Courts.
With nowhere else to go, Namsaeng fled to Tang China at the urge of his son, who had escaped death at the hands of his uncles.
From there he helped lead a Tang-sponsored military campaign into Goguryeo with hopes of regaining power.
[citation needed] Namsaeng's biography (Quan Nan Sheng 泉男生傳) appears in the Xin Tangshu (New History of Tang), book 110.