Western Desert (Egypt) as the "Libyan Desert", taking its name from Ancient Libya, which lay between the Nile and Cyrenaica. With the formation of the state of Libya, the term "Western Desert" has come to describe that part of the Sahara in Egypt. To the Ancient Greeks, the term Libya described the whole Saharan littoral west of the Nile to the Atlas mountains. During Roman times the term Libya was limited to Cyrenaica and the region between there and Egypt, which were organized as the provinces of Libya Superior and Libya Inferior. The term Libyan Desert then applied to the area to the
Arcadia (ancient region) of the Eurotas river. To the south-west, the border with Messania ran along the tops of Mount Nomia, and Mount Elaeum, and from there the border with Elis ran along the valleys of the Erymanthos and Diagon rivers. Most of the region of Arcardia was mountainous, apart from the plains around Tegea and Megalopolis, and the valleys of the Alpheios and Ladon rivers. The Arcadians were an ancient Greek tribe which was situated in the mountainous Peloponnese. It is considered one of the oldest Greek tribes which settled in Greece and it was probably a relative tribe of the proto-Greeks