The Latin name Libya (from Greek Λιβύη, Libyē) referred to the region west of the Nile generally corresponding to the modern Maghreb. Its people were ancestors of the modern Berbers. Berbers occupied the area for thousands of years before the beginning of human records in ancient Egypt. Climate changes affected the locations of the settlements.
More narrowly, Libya could also refer to the country immediately west of Egypt, viz Marmarica (Libya Inferior) and Cyrenaica (Libya Superior). The Libyan Sea or Mare Libycum was the part of the Mediterranean Sea south of Crete, between Cyrene and Alexandria.
In the Hellenistic period, the Berbers were known as Libyans, a Greek term for the inhabitants of the Maghreb. Their lands were called "Libya" and extended from modern Morocco to the western borders of ancient Egypt. Modern Egypt contains the Siwa Oasis, which was part of ancient Libya. Siwi, a Berber language, is still spoken in the area.
The Greek name is based on the ethnonym Libu (Ancient Greek: Λίβυες Líbues, Latin: Libyes). The name Libya (in use since 1934 for the modern country formerly known as Tripolitania and Barca) was the Latin designation for the region of the Maghreb, from the Ancient Greek (Attic Greek: Λιβύη Libúē, Doric Greek: Λιβύᾱ Libúā). In Classical Greece, the term had a broader meaning, encompassing the continent that later (second century BC) became known as Africa, which, in antiquity, was assumed to constitute one third of the world's land mass, compared to Europe and Asia combined.
The Libu are attested since the Late Bronze Age as inhabiting the region (Egyptian R'bw, Punic: 𐤋𐤁𐤉 lby). The oldest known references to the Libu date to Ramesses II and his successor Merneptah, pharaohs of the Nineteenth Dynasty of Egypt, during the 13th century BC. LBW appears as an ethnic name on the Merneptah Stele.
Menelaus had travelled there on his way home from Troy; it was a land of wonderful richness, where the lambs have horns as soon as they are born, where ewes lamb three times a year and no shepherd ever goes short of milk, meat or cheese.
Homer names Libya, in Odyssey (IX.95; XXIII.311). Homer used the name in a geographic sense, while he called its inhabitants "Lotus-eaters". After Homer, Aeschylus, Pindar, and other ancient Greek writers use the name. Herodotus (1.46) used Λιβύη Libúē to indicate the African continent; the Líbues proper were the light-skinned North Africans, while those south of Egypt (and Elephantine on the Nile) were known to him as "Aethiopians"; this was also the understanding of later Greek geographers such Diodorus Siculus, Strabo, etc.