Archeological excavations indicate that France has been continuously settled since Paleolithic times. The Celts, who were later called Gauls by the Romans, migrated from the Rhine valley into what is now France. In about 600 B.C. Greeks and Phoenicians established settlements along the Mediterranean, most notably at Marseille. Julius Caesar conquered part of Gaul in 57–52 B.C., and it remained Roman until Franks invaded in the 5th century A.D.
The Treaty of Verdun (843) divided the territories corresponding roughly to France, Germany, and Italy among the three grandsons of Charlemagne. Charles the Bald inherited Francia Occidentalis, which became an increasingly feudalized kingdom. By 987, the crown passed to Hugh Capet, a princeling who controlled only the Ile-de-France, the region surrounding Paris. For 350 years, an unbroken Capetian line added to its domain and consolidated royal authority until the accession in 1328 of Philip VI, first of the Valois line. France was then the most powerful nation in Europe, with a population of 15 million.
The missing pieces in Philip Valois's domain were the French provinces still held by the Plantagenet kings of England, who also claimed the French crown. Beginning in 1338, the Hundred Years' War eventually settled the contest. After France's victory in the final battle, Castillon (1453), the Valois were the ruling family, and the English had no French possessions left except Calais. Once Burgundy and Brittany were added, the Valois dynasty's holdings resembled modern France. Protestantism spread throughout France in the 16th century and led to civil wars. Henry IV, of the Bourbon dynasty, issued the Edict of Nantes (1598), granting religious tolerance to the Huguenots (French Protestants). Absolute monarchy reached its apogee in the reign of Louis XIV (1643–1715), the Sun King, whose brilliant court was the center of the Western world.
After a series of costly foreign wars that weakened the government, the French Revolution plunged France into a bloodbath beginning in 1789 with the establishment of the First Republic and ending with a new authoritarianism under Napoléon Bonaparte, who had successfully defended the infant republic from foreign attack and then made himself first consul in 1799 and emperor in 1804. The Congress of Vienna (1815) sought to restore the pre-Napoléonic order in the person of Louis XVIII, but industrialization and the middle class, both fostered under Napoléon, built pressure for change, and a revolution in 1848 drove Louis Philippe, last of the Bourbons, into exile. Prince Louis Napoléon, a nephew of Napoléon I, declared the Second Empire in 1852 and took the throne as Napoléon III. His opposition to the rising power of Prussia ignited the Franco-Prussian War (1870–1871), which ended in his defeat, his abdication, and the creation of the Third Republic.