Bánk bán
 ( "Bán" is ban in English , similar to a viceroy , a duke or palatine . ) The main storyline is based on the assassination of Queen Gertrude , wife of Andrew II in 1213 . 
<triplet> Queen Gertrude <subj> Andrew II <obj> spouse <triplet> Andrew II <subj> Queen Gertrude <obj> spouse