Julius Csar and the Illyrians -- The Pannonians on the Danube
At the time when Csar held the command in Gaul these same Dalmatians and other Illyrians, who were then in a very prosperous condition, took the city of Promona 457 from the Liburni, another Illyrian tribe. The latter put 458 themselves in the hands of the Romans and appealed to Csar, who was near by. Csar sent word to those who were holding Promona that they should give it up to the Liburni, and when they refused, he sent against them a strong detachment of his army who were totally destroyed by the Illyrians. Nor did Csar renew the attempt, for he had no leisure then, on account of the civil strife with Pompey. When the civil strife burst forth in war Csar crossed the Adriatic from Brundusium in the winter, with what forces he had, and opened his campaign against Pompey in Macedonia. Antony brought another army to Csar's aid in Macedonia, he also crossing the Adriatic in mid-winter. Gabinius led fifteen cohorts of foot and 3000 horse for him by way of Illyria, passing around the Adriatic. 459 The Illyrians, fearing punishment for what they had done 460 to Csar not long before, and thinking that his victory would be their destruction, attacked and slew the whole army under Gabinius, except Gabinius himself and a few who escaped. Among the spoils captured was a large amount of money and war material.
Csar was preoccupied by the necessity of coming to a conclusion with Pompey, and, after Pompey's death, with the numerous parts of his faction still remaining. When he had settled everything he returned to Rome and made preparations for war with the Get and the Parthians. The Illyrians began to fear lest he should attack them, as they were on his intended line of march. So they sent ambassadors to Rome to crave pardon for what they had done and to offer their friendship and alliance, vaunting themselves 461 as a very brave race. Csar was hastening his preparations 462 against the Parthians; nevertheless, he gave them the dignified answer that he could not make friends of those who had done what they had, but that he would grant them pardon if they would subject themselves to tribute and give him hostages. They promised to do both, and accordingly he sent Vatinius thither with three legions and a large cavalry force to impose a light tribute on them and receive the 463 hostages. When Csar was slain the Dalmatians, thinking 464 that the Roman power resided in him and had perished with him, would not listen to Vatinius on the subject of the tribute or anything else. When he attempted to use force they attacked and destroyed five of his cohorts, including their commanding officer, Bbius, a man of senatorial rank. Vatinius took refuge with the remainder of his force in Epidamnus. The Roman Senate transferred this army, together with the province of Macedonia and Roman Illyria, to Brutus Cpio, one of Csar's murderers, and at the same time assigned Syria to Cassius, another of the assassins. But they also, being involved in war with Antony and the second Csar, surnamed Augustus, had no time to attend to the Illyrians.
The Pones are a great nation on the Danube, extending from the Iapydes to the Dardani. They are called Pones by the Greeks, but Pannonians by the Romans. They are counted by the Romans as a part of Illyria, as I have previously said, for which reason it seems proper that I should include them in my Illyrian history. They have been renowned from the Macedonian period through the Agrianes, who rendered very important aid to Philip and Alexander and are Pones of Lower Pannonia bordering on Illyria. When the expedition of Cornelius against the Pannonians resulted disastrously, so great a fear of those people came over all the Italians that for a long time afterwards none of the consuls ventured to march against them. Concerning the early history of the Illyrians and Pannonians, I have not been able to discover anything further, nor have I found in the commentaries of Augustus anything earlier in the chapters treating of the Pannonians.
I think that other Illyrian tribes besides those mentioned had previously come under Roman rule, but how, I do not know. Augustus did not describe the transactions of others so much as his own, telling how he brought back those who had revolted and compelled them again to pay tribute, how he subjugated others that had been independent from the beginning, and how he mastered all the tribes that inhabit the summits of the Alps, barbarous and warlike peoples, who often plundered the neighboring parts of Italy. It is a wonder to me that so many great Roman armies traversing the Alps to conquer the Gauls and Spaniards, should have overlooked these tribes, and that even Gaius Csar, that most successful man of war, did not despatch them during the ten years that he was fighting the Gauls and wintering in that very country. But the Romans seem to have been intent only upon getting through the Alpine region on the business they were bestirring themselves about, and Csar seems to have delayed putting an end to the Illyrian troubles on account of the Gallic war and the strife with Pompey, which closely followed it. It appears that he was chosen commander of Illyria as well as of Gaul -- not the whole of it, but as much as was then under Roman rule.