King Yeongnyu of Goguryeo, apprehensive about his general Yeon Gaesomun, is plotting with his other officials to kill him in the winter of 642.

When Yeon receives the news, he arranges a lavish banquet to celebrate his rise to the position of Eastern Governor to which one hundred of the opposing politicians of the kingdom are invited.

Yeon's soldiers ambush and kill all one hundred ministers present.

Yeon then proceeds to the palace and murders the king.

According to traditional Chinese and Korean sources, Yeon's men dismembered the dead king's corpse and discarded it without proper ceremony.

After placing a nephew of King Yeongnyu on the Goguryeo throne as King Bojang, Yeon appoints himself Dae Mangniji (Generalissimo).

Subsequently, in this role Yeon goes on to assume de facto control over Goguryeo affairs of state until his death around 666.