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).
Saxons
Schütte also remarks that there was a medieval tradition of calling this area "Old Saxony" (covering Westphalia, Angria and Eastphalia). This view is in line with Bede who mentions Old Saxony was near the Rhine, somewhere to the north of the river Lippe (Westphalia, northeastern part of modern German state Nordrhein-Westfalen).