*The second Illyrian war: 220–219 B. C.* The revival of Macedonian influence led indirectly to Rome’s second Illyrian war. The alliance of Antigonus Doson with the Achaean Confederacy and his conquest of Sparta (222 B. C.) united almost the whole of Greece under Macedonian suzerainty. Thereupon Demetrius of Pharos, a despot whose rule Rome had established in Corcyra, went over to Macedonia, attacked the cities allied with Rome, and sent a piratical squadron into Greek waters (220 B. C.). Rome, now threatened with a second Carthaginian War, acted with energy. Macedonia, under Philip V, the successor of Antigonus Doson, was involved in a war with the Aetolians and their allies. Deprived of support from this quarter Demetrius was speedily driven to take refuge in flight. His subjects surrendered and Rome took possession of his chief fortresses, Pharos and Dimillos. *War with the Gauls in North Italy: 225–22 B. C.* In the interval between these Illyrian Wars Rome became involved in a serious conflict with the Gallic tribes settled in the Po valley. For about half a century this people had lived at peace with Rome, ceasing their raids into the peninsula and becoming a prosperous agricultural and pastoral people. It is claimed that they became alarmed at the Roman assignment of the public land on their southern borders, called the Ager Gallicus, to individual colonists in 233 B. C., and that this caused them to take up arms. However, this territory had been Roman since 283 B. C. and its settlement could hardly have been interpreted as an hostile act. More probable is it that the cause of the new Gallic invasion was the coming of fresh swarms from across the Alps, which some of the Cisalpine Gauls, who had forgotten the defeats of the previous generation, perhaps invited, and certainly joined, for the sake of plunder. In 238 such a band of Transalpines crossed the Roman frontier and penetrated as far as Ariminum, but serious dissensions broke out within their own ranks and they had to withdraw. There was no further inroad attempted until 225 B. C. *The Gallic invasion of 225 B. C.* In that year a formidable horde, called the Gasatae, crossed the Alps and, joined by the Boii and Insubres, prepared to invade Roman territory with a force of 50,000 foot and 20,000 mounted men. The Romans and Italians were seriously alarmed, for the memory of the fatal day of the Allia had never been effaced. Rome called for a military census of her whole federation. The lists showed 700,000 infantry and 70,000 cavalry. Expecting the Gauls to advance into Umbria the Romans stationed an army under one consul at Ariminum. The other consul was sent to Sardinia, possibly from fear of a Carthaginian attack, while the defence of Etruria was left to a force of Roman allies. Alliances were concluded with the Cenomani, a Gallic tribe to the north of the Po, and with the Veneti.