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).
History of Saxony-Anhalt
After Charlemagne's conquest of the Saxons (772–804), their land was incorporated into the Carolingian empire, and late in the 9th century it became the first Duchy of Saxony. It occupied nearly all the territory between the Elbe and Saale rivers to the east and the Rhine to the west; it bordered on Franconia and Thuringia in the south. It was itself divided into four provinces: Westphalia, Angria, Eastphalia, and Nordalbingia, with modern Saxony-Anhalt mostly lying within Eastphalia. Duke Henry I (Henry the Fowler) of Saxony was elected German king in 919, and his son, Emperor Otto I, bestowed (961) Saxony on Hermann Billung (d. 973), a Saxon nobleman, whose descendants held the duchy until the extinction of the male line in 1106. Lothair of Supplinburg bestowed it on his Guelphic son-in-law, Henry the Proud, who was already Duke of Bavaria.
In 1142 the duchy passed to Henry the Lion, son of Henry the Proud. The struggle between Henry the Lion and Emperor Frederick I ended with Henry's loss of all his fiefs in 1180. The stem duchy was broken up into numerous fiefs. The Guelphic heirs of Henry the Lion retained only their allodial lands, the Duchy of Brunswick. The ducal title of Saxony went to Bernhard of Anhalt, a younger son of Albert the Bear of Brandenburg and founder of the Ascanian line of Saxon dukes. Besides Anhalt, Bernard received Lauenburg and the country around Wittenberg on the Elbe. These widely separate territories continued after 1260 under separate branches of the Ascanians as Saxe-Lauenburg and Saxe-Wittenberg.