Hellenic civilization was by now fading rapidly, owing to widespread race-mixing between the Indo-European masters and their aboriginal slaves. In 280 B.C. the Celts moved to take advantage of this decadence. Two Celtic armies routed the Macedonian army. Macedonian resistance ended when a third army of Celts, commanded by another Brennus, arrived the following year to deliver the coup de grace. Brennus' army was estimated at 150,000 foot and up to 20,000 horse and almost certainly included many former mercenaries with experience of Greek military organization.
In any event, having dealt with the Macedonians, Brennus marched on Greece. A largely Athenian army tried to hold the strategic pass at Thermopylae but was defeated much more easily than the Spartans had been two centuries earlier. Town after town went up in flames. Even Delphi was sacked and its sacred oracle looted. Some confusion followed, and Brennus was wounded, according to the Greeks by the god Apollo himself.
The Celts withdrew in good order, but Brennus, disgraced by the withdrawal and injury, committed suicide, and his mighty host broke up. A Celtic kingdom was established in Thrace, but a combination of interbreeding with the earlier inhabitants and pressure from its Greek neighbors meant that it was quickly Hellenized and overwhelmed.
Other Celts took service under various warring Greek rulers or moved northward founding various towns, including Belgrade. A thin line of Celtic placenames even runs along the coast of the Black Sea north of the Danube, with a scattering of La Tene artifacts being found in southern Russia, including a cemetery near Kiev, and as far as the Sea of Azov.
An army of 10,000 Celts with a similar number of dependents were invited to Asia Minor by a local king in 278 B.C. They quickly found it more profitable to operate on their own account, ravaging and extracting tribute from the terrified cities. Their antics were curbed eight years later by a crushing defeat at the hands of a Syrian force equipped with elephants. The majority then settled on a series of poor plateaux henceforth known as Galatia, now in Turkey.
A generation later they backed the losing side in a local civil war and were repeatedly defeated by Attalus of Pergamum. To celebrate the victory, the Greeks created a series of magnificent bronze statues. The Romans copied several of these in marble, including the Dying Gaul of the Capitol and the Ludovisi group showing a Celt, having killed his wife, stabbing himself with his sword rather than surrender.
From then on, the Galatians stayed quietly in their new homeland. For several hundred years though, no prince in the East could do without his corps of Gauls. A revolt in Upper Egypt in 186 B.C. was put down with the help of Gaulish troops. During a lull in the campaign, four of them wandered into a deserted chapel of Horus, leaving grafitti telling how they caught a fox there.
The mercenaries quickly learned Greek, but as late as the fourth century A.D., St. Jerome wrote that the Galatians still also spoke a Celtic dialect similar to that used by the Treviri tribe of the Belgae. Other evidence bears this out. The leaders of the initial invasion and the settlements they founded often had Belgic names, and statues show that many of them wore the wide trousers for which the Belgae were always noted.
