Yelü Dashi
When Yelü Dashi died his wife, Xiao Tabuyan (1143-1150) became regent for their son. The son, Yelü Yilie, ruled from 1150 to 1163, to be succeeded by his sister, Yelü Pusuwan (1164-1177). She then fell in love with her husband's younger brother, Xiao Fuguzhi. They were executed in 1177 by her husband's father, Xiao Wolila, who then placed his son Yelü Zhilugu (1178–1211) on the throne. The empire was weakened by rebellions and internal wars among its vassals, especially during the latter parts of its history.