We need not follow the story of Rome and the Gauls through its details. Time after time we find them leagued with the nations of Italy, when these were at war with the great power which was slowly compelling them either to subjection or to alliance. We find them, for instance, fighting side by side with the Samnites at Sentinum (295 B.C.), and with the Etrurians at the Vadimonian Lake (283 B.C.). But they made no really formidable attack on Rome for a long period after 390. The early part of the third century B.C. was a period of great unrest among the tribes on both sides of the Alps. In 279 this culminated in an invasion of Southern Europe so formidable that though Rome was not immediately concerned with it, some account of it must be given. According to the narrative of Pausanias, who introduces the story as a digression in his description of Delphi, the Gauls invaded Greece under the leadership of a certain Brennus, the same name, it will be observed, as that borne by the conqueror of Rome (the word _Brennus_ has been said to mean "king"; but Celtic scholars are not agreed upon the point). His forces are said to have amounted to 150,000 infantry, a figure on which the authorities are fairly unanimous, and cavalry variously estimated at from 60,000 to 10,000.[31] The Greeks, though in a very depressed condition, roused themselves to resist. It was not a choice, as it had been two centuries before, between freedom and servitude; it was a question of life or death. The barbarians spared no one, and if they could not be checked in their advance, Greece would be turned into a desert. The stand was to be made, as of old, at Thermopylæ. The comparison between the forces led by Leonidas and those now assembled is interesting. The most numerous contingent was from a nation which scarcely appears in the history of Greece at its best days, the Ætolians. "Very numerous and including every arm," says Pausanias. Their heavy-armed infantry numbered 9,000. The other figures he does not give, or they have disappeared from his text. The whole force may have amounted to between thirty and forty thousand. A battle that was fought in the Pass ended greatly to the advantage of the Greeks. The Gauls with their long and unwieldy swords and cumbrous shields were no match for their antagonists, though they fought with desperate valour. Their cavalry, the strongest arm they possessed, could not act on account of the nature of the ground. The result was that they were driven back with very heavy loss, while the Greeks had but forty killed.