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.
Within Libya as many as five different climatic zones have been recognized, but the dominant climatic influences are Mediterranean and Saharan.