Opportune political changes favoured the development of Roman supremacy in Italy. The Etruscan dominion had fallen into utter decay during the course of the fifth century. Rome’s victorious struggle for liberty, the advance of the Samnites in southern Italy, and the immigration of the Gauls into northern Italy, had reduced Etruria to a second-class power. In the south the power of the wealthy Greek cities had been broken by Dionysius of Syracuse. Step by step Roman colonists made their way into lower Italy. Where the sword was of no avail Rome had recourse to road-making, the occupation and cultivation of waste land, and fresh settlements. Above all, the Latin colonies which she established in concert with the Latin league were of the utmost importance in securing the supremacy of Rome in middle Italy. These colonies served as fortresses, the colonists were a garrison always ready to stand on the defensive. The colonies themselves were established in such a way as to obstruct the coalition of the various races of Italy. They spread abroad Latin law and the Latin language among foreigners. They once more united the Romans and Latins in a common work of civilisation, after the two peoples had so hotly fought against each other in what is known as the Great Latin War (340-338 B.C.). The skilful diplomatic negotiations and settlements by which Rome contrived either to gain over her former adversaries or reduce them to neutrality before she engaged in the struggle with the Samnites for the hegemony of Italy (342-340 and 326-304) are particularly worthy of note. She protected her rear by concluding armistices for many years with the Etruscans (351-311) and Gauls (329-299). She entered into friendly relations with the Greek cities, and won over many communities in Campania and Lucania which had put themselves under the protection of the Samnites. Nay, she did not shrink from purchasing the friendship of Carthage by allowing her to take and plunder the seaboard cities of middle Italy which had revolted against Roman dominion. And she further displayed remarkable skill in securing her tenure of the possessions won in the Samnite wars. Only a small part of them was incorporated with Roman territory. Many cities received an accession of Latin colonists and so retained their municipal autonomy under new conditions. On the other hand the connection between the recalcitrant cantons of the Sabellian, Etruscan, and Middle Italian tribes was completely broken. Isolated and deprived of the right of intercourse (_commercium_) the various small cities and communities ceased to be of any importance either economically or politically. The Romans had hardly completed the conquest of Etruria and the Samnite confederacy in the Third Samnite War (298-290 B.C.), and subjugated the kindred districts of Lucania and Bruttium when they found themselves involved in the struggles which then agitated the Greek world.