 He had three sisters and six brothers, the best known of whom were Prince-Archbishop Siegfried of Bremen, and Count Bernhard of Anhalt, later Duke of Saxony.Otto's year of birth is traditionally recorded as 1128, but recent historians have cast some doubts on the date.Pribislav of the Havolanes is known to have served as Otto's godfather and given the lands of Zauche bordering the Ascanian possessions as a gift upon the occasion; Partenheimer (2003) dates that event to 1123 or 1125.