Upper Saxony
It was particularly to distinguish the lands from 'Lower Saxony', a concept which arose later in popular usage (though never enforced) as a term for the original Saxon lands in north and west Germany (where Low German dialects had spread), in what is now the state of Lower Saxony, as well as the adjacent Westphalian region, Holstein and the western part of today's Saxony-Anhalt north of the Harz range (Eastphalia).
Siegfried, Prince-Archbishop of Bremen
In 1180, at the Diet in Gelnhausen, the attending princes and "Frederick I Barbarossa" decided to partition Saxony in some dozens of territories of imperial immediacy, allotting each territory to that one of his allies, who had conquered them before from "Henry the Lion" and his remaining supporters. Otto I wielded his influence at the Diet. His and Siegfried's brother Bernhard, one of the most steadfast warriors against Henry "the Lion", was provided with the later on so-called younger "Duchy of Saxony" (1180 - 1296), thus becoming "Bernhard III, Duke of Saxony". In 1260, with effect from 1296 on, its later rulers split the "younger Duchy" into the Duchies of Saxe-Wittenberg () and Saxe-Lauenburg (), the latter belonging in religious respect to the "archdiocese of Bremen".