Paris is the capital of France. It lies at the heart of a vast fertile plain to the temperate climate, the Paris Basin, on a loop of the Seine, between the confluence of the latter with the Marne and Oise. Its inhabitants are called Parisians. Paris is also the capital of the region Île-de-France and the French joint single is also a department. As the French cities of Lyon and Marseille, it is divided into districts, twenty in number, and has a police commissioner. Long city most populated in Europe, it remains the most populated of France and one of the most populated European cities. According to the census of INSEE, the commune of Paris was on 1 January 2013 more than 2.2 million. The Paris area has largely developed during the twentieth century, collecting 10.6 million at 1 January 2012, and its urban area (agglomeration and urban periphery) had 12.4 million inhabitants January 1, 2013.The history of Paris is linked to the combination of several geographical and political factors. This is Clovis decides, in the sixth century, to install fixed organs of political power of the kingdom in the small city of the Parisian. This capital position will be confirmed by the Capetians, after a hiatus of two centuries the Carolingian era.