Since the Duke of Saxony was considered one of the prince-electors electing a new Holy Roman Emperor, there was an argument between the lines of Lauenburg and Wittenberg about who should cast Saxony's vote. In 1314 both lines found themselves on different sides in a double election. Eventually, the Dukes of Saxe-Wittenberg succeeded in 1356 after the promulgation of the Golden Bull. To distinguish him from other rulers bearing the title Duke of Saxony, he was commonly called "Elector of Saxony".