Zwentibold or Zventibold, Swentiboldo, Sventibaldo, Sanderbald, 1 January 870 – 13 August 900 was the illegitimate son of the Carolingian Emperor Arnulf of Carinthia. 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.