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).
Lusatia
In 1945, the northeastern part of Upper Lusatia west of the Neisse rejoined Saxony and in 1952, when the state was divided into three administrative areas ("Bezirke"), the Upper Lusatian region became part of the Dresden administrative region. After the East German Revolution of 1989, the state of Saxony was reestablished in 1990. Lower Lusatia remained with Brandenburg, from 1952 until 1990 in the "Bezirk" of Cottbus.