Wikipedia
Zwentibold
Zwentibold (Zventibold, Swentiboldo, Sventibaldo, Sanderbald; – 13 August 900), a member of the Carolingian dynasty, was the illegitimate son of Emperor Arnulf. In 895, his father, then king of East Francia, granted him the Kingdom of Lotharingia, which he ruled until his death. After his death he was declared a saint and martyr by the Catholic Church.