As the Billung male line became extinct upon Magnus's death in 1106, Otto hoped to succeed him, however King Henry V of Germany enfeoffed Count Lothair of Supplinburg.

Lothair was elected King of the Romans in 1125 and in 1134 he vested Otto's son Albert the Bear with the Saxon Northern March.

Upon his death in 1137, Albert once again strived for the Saxon duchy, which however fell to Lothair's son-in-law Henry the Proud from the Bavarian House of Welf.

The Saxon ducal title at least passed to late Albert's youngest son, Count Bernhard of Ballenstedt, who nevertheless only ruled over small, mostly Eastphalian fringes of the old duchy.

Duke Bernard died in 1212 and his two surviving sons divided the Saxon heritage: the elder Henry took the old Ascanian allodial possessions around Ballenstedt where he established the Ascanian County of Anhalt, while his younger brother Albert I inherited the title of a Duke of Saxony and retained three territorially unconnected Eastphalian estates on the Elbe river around the towns of Wittenberg and Belzig as well as the northern lordship of Lauenburg with Amt Neuhaus and Land Hadeln at the Elbe estuary.

The last document, mentioning the joint government of Albert II with his nephews as Saxon fellow dukes dates back to 1295.

In 1314 both duchies participated in the double election of the German kings, Frederick III, the Fair from the House of Habsburg and his Wittelsbach cousin Louis IV, the Bavarian.

Frederick the Fair received in the same election four of the seven votes, with the deposed King Henry of Bohemia, illegitimately assuming electoral power, Archbishop Henry II of Cologne, Louis' brother Count Rudolph I of the Palatinate, and Duke Rudolph I of Saxe-Wittenberg, equally exercising the Saxon electoral dignity.

However, only Louis the Bavarian, co-elected with Saxe-Lauenburg's vote, finally asserted himself as emperor after the 1322 Battle of Mühldorf by the Treaty of Trausnitz on March 13, 1325.