<page_title> List of legendary kings of Britain </page_title> <section_title> Kings derived from Geoffrey of Monmouth </section_title> <table> <cell> Constantine III <col_header> Kingdom </col_header> <col_header> England </col_header> <col_header> Scotland </col_header> <col_header> Wales </col_header> <col_header> Cornwall </col_header> </cell> </table>
Constantine III (Western Roman Emperor) was a King of the Britain who derived from Geoffrey of Monmouth's.