Modern France covers approximately the same territory as ancient Gaul, an area inhabited by Celtic peoples. Gaul was then a prosperous country, of which the southernmost part was heavily subject to Greek and Roman influences. From the beginning of the 5th century, Germanic tribes crossed the Rhine and settled in Gaul and other parts of the decaying Roman Empire. The pagan Franks, from whom the ancient name of "Francia" was derived, originally settled the northern part of Gaul, but subsequently conquered most of the other kingdoms in northern and central Gaul. The Merovingian kings united the Frankish tribes then were displaced by the Carolingians -  Charlemagne, reunited the Frankish kingdoms and built a vast empire across western and central Europe, being named as Holy Roman Emperor by the Pope.

The French monarchy reached its peak during the 17th century during the reign of Louis XIV. France then had the largest population in Europe and had influenced most European politics, economy, and culture. French language became the common tongue for diplomacy, science, literature and international affairs.

The 1789 French revolution ended absolute monarchy and focused on the new philosophy of the "rights of man" and the principle of social equality among citizens.  Napoleon Bonaparte seized power in the new republic and as Emperor led an international expansion of French ideals and reforms.

In the 19th and 20th centuries, the French overseas colonial empire extended greatly, becoming the second largest in the world after the British Empire.

The first half of the 20th century saw two world wars in which France paid a very high price in economic and human terms; the second half was beset with the difficulties of decolonisation and driven by reconciliation and co-operation with Germany, central to the development of the European Union.  France was one of the six founding members of the EU on 25th March 1957 and joined the €urozone in 1999.

In the early 21st century, five French overseas territories - French Guiana, Guadeloupe, Martinique, Mayotte and Réunion - became French regions and were made part of France.