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).
List of rulers of Saxony
The original Duchy of Saxony comprised lands of the Saxon people in the north-western part of present-day Germany, namely, the contemporary German state of Lower Saxony as well as Westphalia and Western Saxony-Anhalt, not corresponding to the modern German state of Saxony.With the removal of the Welfs in 1180, the Duchy of Saxony was sharply reduced in territory. Westphalia fell to the Archbishop of Cologne, while the Duchy of Brunswick remained with the Welfs. The Ascanian Dukes had their base further east, near the Elbe, in what is sometimes called the "younger Duchy of Saxony", resulting in the name Saxony moving towards the east.