However , he is of the Bian ( Uiseong ) Bak clan .
Bak 's grandfather is Bak Yun - bo Bak 's his father is Bak Jeom with the title of Jungnyangjang ( a military post ) .
However , he is of the Bian ( Uiseong ) Bak clan , and his grandfather is Bak Yun - bo and his father is Bak Jeom with the title of Jungnyangjang ( a military post ) .