The first written records for the history of France appeared in the Iron Age. What is now France made up the bulk of the region known to the Romans as Gaul. Greek writers noted the presence of three main ethno-linguistic groups in the area: the Gauls, Aquitani and Belgae. Over the first millennium BC the Greeks, Romans and Carthaginians established colonies on the Mediterranean coast and offshore islands. The Roman Republic annexed southern Gaul in the late 2nd century BC, and legions under Julius Caesar conquered the rest of Gaul in the Gallic Wars of 58–51 BC. A Gallo-Roman culture emerged, and Gaul was increasingly integrated into the Roman Empire. In the later stages of the empire, Gaul was subject to barbarian raids and migration. The Frankish king Clovis I united most of Gaul in the late 5th century. Frankish power reached its fullest extent under Charlemagne. The medieval Kingdom of France emerged from the western part of Charlemagne's Carolingian Empire, known as West Francia, and achieved increasing prominence under the rule of the House of Capet, founded in 987. The monarchy initially wielded only limited authority, but Philip II of France brought the Angevin Empire to an end by defeating a coalition of his rivals at the Battle of Bouvines in 1214. Following this victory, France became the most prosperous and powerful kingdom in Europe.
A succession crisis in 1328 led to the Hundred Years' War between the House of Valois and the House of Plantagenet. The war began in 1337 following Philip VI's attempt to seize the Duchy of Aquitaine from its hereditary holder Edward III of England, the Plantagenet claimant to the French throne. A notable figure of the war was Joan of Arc, a French peasant girl who led forces against the English, establishing herself as a national heroine. The war ended with a Valois victory in 1453, strengthening French nationalism and increasing the power and reach of the French monarchy. During the Ancien Régime over the next centuries, France transformed into a centralized absolute monarchy through the Renaissance and Reformation. At the height of the French Wars of Religion, France became embroiled in another succession crisis, as the last Valois king, Henry III, fought against factions of the House of Bourbon and House of Guise. Henry, the Bourbon King of Navarre, won and established the Bourbon dynasty. A burgeoning worldwide colonial empire was established in the 16th century.
By the mid-17th century, France had emerged as the dominant hegemonic power in Europe, building Europe's strongest army, engaging in a series of wars, and undergoing a period of artistic and scientific development. In the late 18th century the monarchy and associated institutions were overthrown in the French Revolution. The Revolutionary Tribunal executed political opponents by guillotine, instituting the Reign of Terror (1793–94). The country was governed as a Republic, until Napoleon's French Empire was declared in 1804. Following his defeat in the Napoleonic Wars, France went through regime changes, being ruled as a monarchy, then Second Republic, then Second Empire, until a more lasting French Third Republic was established in 1870.
During World War I, France played a decisive role in defeating the Central Powers as part of the Triple Entente, while participating in the majority of the war's major battles fought on the Western Front. France during World War II was one of the Allied Powers but was conquered by Nazi Germany in 1940. The Third Republic was dismantled, and most of the country was controlled directly by Germany, while the south was controlled until 1942 by the collaborationist Vichy government. Following liberation in 1944, the Fourth Republic was established. France slowly recovered and enjoyed a baby boom that reversed its low fertility rate. Long wars in Indochina and Algeria drained French resources and ended in political defeat. In the wake of the 1958 Algerian crisis, Charles de Gaulle set up the French Fifth Republic. Into the 1960s most of the French colonial empire became independent, while smaller parts were incorporated into the French state as overseas departments and collectivities. Since World War II France has been a permanent member in the UN Security Council and NATO. It played a central role in the unification process after 1945 that led to the European Union. It remains a strong economic, cultural, military and political factor in the 21st century.
Stone tools discovered at Chilhac and Lézignan-la-Cèbe indicate that pre-human ancestors may have been present in France at least 1.6 million years ago. Neanderthals were present in Europe from about 400,000 BC but died out about 40,000 years ago, possibly out-competed by modern humans during a period of cold weather. The earliest evidence of modern humans in France was found at the Mandrin Cave and has been dated to between 56,800 and 51,700 years ago.
In the Chalcolithic and early Bronze Age the territory was largely dominated by the Bell Beaker culture, followed by the Armorican Tumulus culture, Rhône culture, Tumulus culture, Urnfield culture and Atlantic Bronze Age culture, among others. The Hallstatt culture and La Tène culture developed during the Iron Age, during which the first written records for the history of France appear.
In 800 BC, Ionian Greeks founded the colony of Massalia (present-day Marseille) on the shores of the Mediterranean Sea, making it one of the oldest cities in France. At the same time, some Celtic tribes arrived in the eastern parts (Germania Superior) of the region and spread to the rest of France between the 5th and 3rd century BC.
Covering large parts of modern-day France, Belgium, northwest Germany and northern Italy, Gaul was inhabited by many Celtic and Belgae tribes of whom the Romans referred as Gauls and who spoke the Gaulish language roughly between the Oise and the Garonne, according to Julius Caesar. On the lower Garonne the people spoke Aquitanian, a Pre-Indo-European language related to (or a direct ancestor of) Basque whereas a Belgian language was spoken north of Lutecia but north of the Loire according to other authors like Strabo. The Celts founded cities such as Lutetia Parisiorum (Paris) and Burdigala (Bordeaux) while the Aquitanians founded Tolosa (Toulouse).
Long before any Roman settlements, Greek navigators settled in what would become Provence. The Phoceans founded important cities such as Massalia (Marseille) and Nikaia (Nice), bringing them into conflict with the neighboring Celts and Ligurians. The Celts often fought with Aquitanians and Germans, and a Gaulish war band led by Brennus invaded Rome following the Battle of the Allia.
However, the tribal society of the Gauls did not change fast enough for the centralized Roman state. The Gaulish tribal confederacies were defeated by the Romans in battles such as Sentinum and Telamon during the 3rd century BC. In the early 3rd century BC, some Belgae (Germani cisrhenani) conquered the surrounding territories of the Somme in northern Gaul after battles supposedly against the Armoricani (Gauls) near Ribemont-sur-Ancre and Gournay-sur-Aronde, where sanctuaries were found.
When Carthaginian commander Hannibal fought the Romans, he recruited several Gaulish mercenaries who fought on his side at Cannae. It was this Gaulish participation that caused Provence to be annexed in 122 BC by the Roman Republic. As the Consul of Gaul, Julius Caesar conquered all of Gaul. Despite Gaulish opposition led by Vercingetorix, the Gauls succumbed to the Roman onslaught. The Gauls had some success at first at Gergovia but were ultimately defeated at Alesia in 52 BC. The Romans founded cities such as Lugdunum (Lyon), Narbonensis (Narbonne) and allowed in a correspondence between Lucius Munatius Plancus and Cicero to formalize the existence of Cularo (Grenoble).
Gaul was divided into several different provinces. The Romans displaced populations to prevent local identities from becoming a threat to Roman control. Thus, many Celts were displaced in Aquitania or were enslaved and removed from Gaul. There was a strong cultural evolution in Gaul under the Roman Empire, the most obvious one being the replacement of the Gaulish language by Vulgar Latin. It has been argued the similarities between Gaulish and Latin favoured the transition. Gaul remained under Roman control for centuries, and Celtic culture was then gradually replaced by Gallo-Roman culture.