Yeon Gae Somun is the general who killed the penultimate King of Goguryeo, Yeongnyu, in 642. It was a period of tremendous instability, both because of the pressure by Shilla, but also because the political situation in Goguryeo was very confusing. After General Yeon put Yeongnyu's nephew Bojang as his puppet on the throne following his coup d'etat, he tried with little success to calm down Yeon's two sons in trying to gain power, and started repressing Buddhism (the Kingdom's official religion) in favour of Taoism.