Libya, the Greek name for the northern part of Africa, with which alone Greek and Roman history are concerned. It is mentioned as a land of great fertility in Homer (Odyssey, iv. 85), but no indication of its extent is given. It did not originally include Egypt, which was considered part of Asia, and first assigned to Africa by Ptolemy, who made the isthmus of Suez and the Red Sea the boundary between the two continents. The name Africa came into general use through the Romans. In the early empire, North Africa (excluding Egypt) was divided into Mauretania, Numidia, Africa Propria and Cyrenaica. The old name was reintroduced by Diocletian, by whom Cyrenaica (detached from Crete) was divided into Marmarica (Libya inferior) in the east, and Cyrenaica (Libya superior) in the west. A further distinction into Libya interior and exterior is also known. The former (ἡ ἐντός) included the interior (known and unknown) of the continent, as contrasted with the N. and N.E. portion; the latter (ἡ ἔξω, called also simply Libya, or Libyae nomos), between Egypt and Marmarica, was so called as having once formed an Egyptian “nome.” See Africa, Roman.