Algeria. Algeria, officially the People's Democratic Republic of Algeria, is a country in the Maghreb region of North Africa. The capital and most populous city is Algiers, located in the far north of the country on the Mediterranean coast. With an area of 2,381,741 square kilometres, Algeria is the tenth-largest country in the world, and the largest by area in the African Union and the Arab world. With an estimated population of over 44 million, it is the eighth-most populous country in Africa. Algeria is bordered to the northeast by Tunisia, to the east by Libya, to the southeast by Niger, to the southwest by Mali, Mauritania, and the Western Saharan territory, to the west by Morocco, and to the north by the Mediterranean Sea. The country has a semi-arid geography, with most of the population living in the fertile north and the Sahara dominating the geography of the south. This arid geography makes the country very vulnerable to climate change. Pre-1962 Algeria has known many empires and dynasties, including ancient Numidians, Phoenicians, Carthaginians, Romans, Vandals, Byzantines, Umayyads, Abbasids, Idrisid, Aghlabid, Rustamid, Fatimids, Zirid, Hammadids, Almoravids, Almohads, Zayyanids, Spaniards, Ottomans and finally, the French colonial empire. Most of the population is Arab-Berber, practicing Islam and using the official languages of Arabic and Berber. However, French serves as a administrative and education language in some contexts, and Algerian Arabic is the main spoken language. Algeria has a semi-presidential republic, with local constituencies consisting of 48 provinces and 1,541 communes. Algeria is a regional and middle power. It has the highest human development index of all non-island African countries and one of the largest economies on the continent, based largely on energy exports. Algeria has the 16th largest oil reserves in the world and the second largest in Africa, while it has the ninth largest reserves of natural gas. Sonatrach, the national oil company, is the largest company in Africa, supplying large amounts of natural gas to Europe. Algeria has one of the largest militaries in Africa and the largest defence budget. It is a member of the African Union, the Arab League, OPEC, the United Nations, and the Arab Maghreb Union, of which it is a founding member. In the region of Ain Hanech, early remnants of hominid occupation in North Africa were found. Neanderthal tool makers produced hand axes in the Levalloisian and Mousterian styles similar to those in the Levant. Algeria was the site of the highest state of development of Middle Paleolithic Flake tool techniques. Tools of this era, starting about 30,000 BC, are called Aterian. The earliest blade industries in North Africa are called Iberomaurusian. This industry appears to have spread throughout the coastal regions of the Maghreb between 15,000 and 10,000 BC. Neolithic civilization developed in the Saharan and Mediterranean Maghreb perhaps as early as 11,000 BC or as late as between 6000 and 2000 BC. This life, richly depicted in the Tassili n'Ajjer paintings, predominated in Algeria until the classical period. The mixture of peoples of North Africa coalesced eventually into a distinct native population that came to be called Berbers, who are the indigenous peoples of northern Africa. From their principal center of power at Carthage, the Carthaginians expanded and established small settlements along the North African coast; by 600 BC, a Phoenician presence existed at Tipasa, east of Cherchell, Hippo Regius and Rusicade. These settlements served as market towns as well as anchorages.