Libya, officially the State of Libya, is a sovereign state in North Africa, bordered by the Mediterranean Sea to the north, Egypt to the east, Sudan to the southeast, Chad and Niger to the south and Algeria and Tunisia to the west. The country is made of three historical regions: Tripolitania, Fezzan and Cyrenaica. With an area of almost 1.8 million square kilometres, Libya is the fourth largest country in Africa, and is the 16th largest country in the world. Libya has the 10th-largest proven oil reserves of any country in the world. The largest city and capital, Tripoli, is located in western Libya and contains over one million of Libya's six million people. The second-largest city is Benghazi, which is located in eastern Libya.
Libya has been inhabited by Berbers since the late Bronze Age. The Phoenicians established trading posts in western Libya, and ancient Greek colonists established city-states in eastern Libya. Libya was variously ruled by Carthaginians, Persians, Egyptians and Greeks before becoming a part of the Roman Empire. Libya was an early centre of Christianity.