<page_title> List of monarchs of Northumbria </page_title> <section_title> Kings of Northumbria in the Norse era </section_title> <table> <cell> Siefredus <col_header> Incumbent </col_header> </cell> <cell> Sigfroðr in Old Norse. <col_header> Notes </col_header> </cell> </table>
Siefredus (Old Norse: Sigfrøðr) was the Norse King of Northumbria.