The Gauls emerged around the 5th century BC as bearers of La Tène culture north and west of the Alps. Their homeland was known as Gaul, a region stretching across what is now France, Belgium, Switzerland, Southern Germany, Austria, and the Czech Republic. By the 4th century BC, these tribes controlled trade routes along major river systems including the Rhône, Seine, Rhine, and Danube. This network allowed them to spread their influence far beyond their original heartland. The Urnfield culture from , 750 BC represents the Celts as a distinct cultural branch of Indo-European-speaking people. Iron working led to the Hallstatt culture in the 8th century BC, which evolved into La Tène culture by the 5th century BC. Greek and Etruscan civilizations began influencing the Gauls, especially in Mediterranean areas. Gallic invaders settled the Po Valley in the 4th century BC and defeated Roman forces under Brennus in 390 BC. They raided Italy as far south as Sicily during this period of expansion.
Military Expansions And Wars
During the Balkan expedition, Gaulish leaders Cerethrios, Brennos, and Bolgios led raids against the Greek mainland twice. In the first invasion of Greece in 279 BC, they defeated Macedonians and killed King Ptolemy Keraunos. The Gauls focused on looting rich Macedonian countryside while avoiding heavily fortified cities. A Macedonian general named Sosthenes assembled an army that defeated Bolgius and repelled the invading forces. During the second invasion in 278 BC, the Gauls suffered heavy losses at Thermopylae but managed to encircle the Greek army using mountain paths around the pass. After passing through Thermopylae, they headed for the treasury at Delphi where they were defeated by a reassembled Greek army. The leader Brennos was seriously injured at Delphi and committed suicide there. Survivors fled from Greece back toward Macedonia and eventually Asia Minor. About 10,000 fighting men and an equal number of women and children settled in Central Anatolia after being invited by Nicomedes I of Bithynia in 278 BC. These settlers divided into three tribes: Trocmi, Tolistobogii, and Tectosages. They faced defeat by Seleucid king Antiochus I in 275 BC when his war elephants shocked the Galatian forces.