Albert 's sons divided Saxony into the duchies of Saxe-Lauenburg and Saxe-Wittenberg .
In 1260 Albert bequeathed the duchy to his sons John I and Albert II , who gradually divided Saxony into the duchies of Saxe-Lauenburg and Saxe-Wittenberg with definite effect of 1296 . Saxe-Wittenberg was recognized as the electorate of Saxony in the Golden Bull of 1356 .