In B.C. 223 the Romans for the first time crossed the Po, and the Consul C. Flaminius gained a brilliant victory over the Insubres. The Consuls of the next year, Cn. Cornelius Scipio and M. Claudius Marcellus, continued the war against the Insubres, who called in to their aid a fresh body of Transalpine Gauls. Marcellus slew with his own hand Viridomarus, the chief of the Insubrian Gauls, and thus gained the third _Spolia Opima_. At the same time Scipio took Mediolanum (Milan), the chief town of the Insubres. This people now submitted without conditions, and the war was brought to an end. To secure their recent conquests, the Romans determined to plant two powerful Latin colonies at Placentia and Cremona, on opposite banks of the Po. These were founded in B.C. 218, and consisted each of 6000 men. The Via Flaminia, a road constructed by C. Flaminius during his consulship (B.C. 220), from Rome to Ariminum, secured the communication with the north of Italy. While the Romans were engaged in the Gallic wars, the traitor Demetrius of Pharos had usurped the chief power in Illyria, and had ventured upon many acts of piracy. In B.C. 219 the Consul L. AEmilius Paullus crossed the Adriatic, and soon brought this second Illyrian war to an end. Demetrius fled to Philip of Macedon, where we shall shortly afterward see him prompting this king to make war against Rome. The greater part of Illyria was restored to the native chiefs; but the Romans retained possession of Corcyra, and of the important towns of Apollonia and Oricum on the coast.