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).
Old Saxony
However, other copies call the same tribe "Axones", and it is considered likely that it is a misspelling of the tribe that Tacitus in his "Germania" called "Aviones". These earliest known tribal Saxons inhabited "Northern Albingia", a region bordering the northern bank of the mouth of River Elbe in what is now Western Holstein. As land became scarce, the Saxon population began to expand southward where it absorbed indigenous populations such as Cherusci, Chamavi and Chatti, and remaining portions of the Langobardi (Lombards) and Suebi. This broader domain is called "Old Saxony". The Chauci, according to Tacitus, also lived in the general area later known as "Old Saxony" and were highly respected among Germanic tribes. He describes them as peaceful, calm, and levelheaded. At some point they may have merged with, or were perhaps synonymous to, the Saxons.