Six martyred ministers
Both King Sejong and King Munjong had charged them with looking after King Danjong ( grandson and son respectively ) , and they reacted with outrage to Sejo's usurpation of the throne in 1455 . 
<triplet> King Munjong <subj> King Danjong <obj> child <triplet> King Danjong <subj> King Munjong <obj> father