Libya is a large country with a relatively small population, but the population is concentrated very narrowly along the coast. Population density is about 50 persons per km² (130/sq. mi.) in the two northern regions of Tripolitania and Cyrenaica, but falls to less than one person per km² (2.6/sq. mi.) elsewhere.
Historically the area of Libya was considered three provinces (or states), Tripolitania in the northwest, Barka (Cyrenaica) in the east, and Fezzan in the southwest. It was the conquest by Italy in the Italo-Turkish War that united them in a single political unit.
Deficiency in rainfall is reflected in an absence of permanent rivers or streams, and the approximately twenty perennial lakes are brackish or salty.