France (French IPA), is a country whose territory consists of metropolitan France in western Europe, as well as several overseas regions and territories. The metropolitan area of France extends from the Mediterranean Sea to the English Channel and the North Sea, and from the Rhine to the Atlantic Ocean. The overseas territories include French Guiana in South America and several islands in the Atlantic, Pacific and Indian oceans. The country's 18 integral regions (5 of which are situated overseas) span a combined area of 643,801 square kilometres (248,573 sq mi) which, as of January 2017, has a total population of almost 67 million people. France is a unitary semi-presidential republic with its capital in Paris, the country's largest city and main cultural and commercial centre. Other major urban centres include Marseille, Lyon, Lille, Nice, Toulouse and Bordeaux. During the Iron Age, what is now metropolitan France was inhabited by the Gauls, a Celtic people. The area was annexed in 51 BC by Rome, which held Gaul until 486, when the Germanic Franks conquered the region and formed the Kingdom of France. France emerged as a major European power in the Late Middle Ages, with its victory in the Hundred Years' War (1337 to 1453) strengthening state-building and political centralisation. During the Renaissance, French culture flourished and a global colonial empire was established, which by the 20th century would be the second largest in the world. The 16th century was dominated by religious civil wars between Catholics and Protestants (Huguenots). France became Europe's dominant cultural, political, and military power under Louis XIV. In the late 18th century, the French Revolution overthrew the absolute monarchy, established one of modern history's earliest republics, and saw the drafting of the Declaration of the Rights of Man and of the Citizen, which expresses the nation's ideals to this day. In the 19th century Napoleon took power and established the First French Empire, whose subsequent Napoleonic Wars shaped the course of continental Europe. Following the collapse of the Empire, France endured a tumultuous succession of governments culminating with the establishment of the French Third Republic in 1870. France was a major participant in the First World War, from which it emerged victorious, and was one of the Allied Powers in the Second World War, but came under occupation by the Axis Powers in 1940. Following liberation in 1944, a Fourth Republic was established and later dissolved in the course of the Algerian War. The Fifth Republic, led by Charles de Gaulle, was formed in 1958 and remains to this day. Algeria and nearly all the other colonies became independent in the 1960s and typically retained close economic and military connections with France. France has long been a global centre of art, science, and philosophy. It hosts Europe's fourth-largest number of cultural UNESCO World Heritage Sites and receives around 83 million foreign tourists annually, the most of any country in the world. France is a developed country with the world's sixth-largest economy by nominal GDP and ninth-largest by purchasing power parity. In terms of aggregate household wealth, it ranks fourth in the world. France performs well in international rankings of education, health care, life expectancy, and human development. France remains a great power in the world, being one of the five permanent members of the United Nations Security Council with the power to veto and an official nuclear-weapon state. It is a leading member state of the European Union and the Eurozone. It is also a member of the Group of 7, North Atlantic Treaty Organization (NATO), Organisation for Economic Co-operation and Development (OECD), the World Trade Organization (WTO), and La Francophonie.