In the middle of Goguryeo's power struggles between Yeon Gaesomun's successors, his younger brother, Yeon Jeongto, defected to the Silla side.
I midten af ​​Goguryeos magtkampe mellem Yeon Gaesomun efterfølgere, hoppede hans yngre bror, Yeon Jeongto, af til Silla.