Titus Livius (Livy), The History of Rome, Book 38
Evan T. Sage, Ph.D., Ed.

16. The Gauls,¹ a vast horde of men, whether moved by shortage of land or hope of plunder, feeling assured that no people through which they would pass was their match in war, under the leadership of Brennus came into the country of the Dardanians.² [2] There strife broke out among them; about twenty thousand men, with Lonorius and Lutarius as their chiefs, seceded from Brennus and turned aside into Thrace. [3] There, when they had penetrated as far as Byzantium, contending against those who resisted and imposing tribute upon those who sought peace, they occupied for a considerable time the coast of the Propontis, holding as tributaries the cities of the district. [4] Then the desire of crossing into Asia seized them, as they heard from their [p. 53]neighbours how rich was this land; and having taken³ Lysimachia by treachery and occupied the whole Chersonesus by force of arms they came down to the Hellespont. [5] There, as they saw Asia separated from them by a narrow strait, their souls were even more inflamed with the desire to cross, and they sent messengers to Antipater, the prefect of this coast, regarding the crossing. [6] When this negotiation was dragging out longer than they had expected, another new revolt broke out between the chiefs. Lonorius with the larger part of the men went back to Byzantium whence he had come; Lutarius, when Macedonians were sent by Antipater to spy, under cover of being an embassy, took from them two decked ships and three cruisers. Using these as ferry-boats day after day and night after night, within a few days he transported his entire force. [7] Only a little later Lonorius, with the aid of Nicomedes,⁴ king of Bithynia, crossed from Byzantium. Then the Gauls were once more united and aided Nicomedes in the war he was waging against Ziboetas, who held some part of Bithynia. [8] And, principally as a result of their assistance, Ziboetas was conquered and all Bithynia acknowledged the sovereignty of Nicomedes. [9] Setting out from Bithynia they made their way into Asia. Of their twenty thousand men, not more than ten thousand were armed. Nevertheless, they inspired such terror in all the peoples who dwell on this side of the Taurus, those whom they approached and those whom they did not approach, that the most distant and the nearest alike obeyed their orders. [10] Finally, since there were three tribes, the Tolostobogii, the Trocmi, and the Tectosages, they split [p. 55]up into three divisions, according to the states of Asia⁵ which each held as tributaries. [11] To the Trocmi the coast of the Hellespont was assigned; the Tolostobogii received by the lot Aeolis and Ionia, the Tectosages the interior parts of Asia. [12] And they exacted tribute from all Asia on this side of the Taurus, but established their own dwellings along the river Halys.⁶ [13] And so great was the terror of their name, their numbers being also enlarged by great natural increase, that in the end even the kings of Syria⁷ did not refuse to pay them tribute. Attalus, the father of King Eumenes, was the first of the inhabitants of Asia to refuse, and his bold step, contrary to the expectation of all, was aided by fortune and he worsted the Gauls in pitched battle.⁸ [14] Yet he did not cow them so thoroughly that they refrained from exercising their power;⁹ their strength remained the same until the war between Antiochus and the Romans. [15] Even then, after the defeat of Antiochus, they entertained great hopes that, since they lived far from the sea, the Roman army would not march against them.