A full description of the various military campaigns of Rome would tend to obscure rather than to illumine the political and economic history of the city. An enumeration of the foreign conquests of Rome during this period, however, is necessary to indicate the rapid increase in the territorial possessions of Rome, with their inevitable reaction upon the domestic conditions of the republic.
The first wars of Rome after the passage of the Licinian Laws were renewed contests with her neighboring enemies. In 361 B.C. Rome was again threatened by a new invasion of the Gauls. The following year the Roman records mention a victory over the Hernicans by one Roman consul, and over the Gauls, and the Latins of Tibur, by the other. This alliance of the Gauls with a portion of the Latins so alarmed the majority of the Latin cities that a new league between the Romans and Latins was formed in 358 B.C. The Gauls soon after retired from the neighborhood of Latium, and their allies, Tibur and Privernum, were compelled to enter the new Latin League.
A war waged against Rome by the Etruscan city of Tarquinii and its allies so seriously threatened Rome that the Roman political factions forgot their differences so far as to agree to the appointment (for the first time in the history of the city) of a plebeian, in the person of C. Marcius Rutilus, to the office of dictator. The old jealousy of the patricians, however, was soon manifested again in the opposition of the Senate to the granting of a triumph to this plebeian for the great military victory which he soon won.
In 350 B.C. a third invasion of the Gauls was repulsed by the Romans.
The next great contest in which Rome was engaged was that with the Samnites. This race was both the most worthy and the most bitter of the enemies of Rome within Italy, and the long warfare between Rome and the Samnites was terminated only by the practical extermination of the latter race. The First Samnite War extended from 343 to 341 B.C. and was indecisive in its results, the Samnites at its close agreeing to give a year's pay and three months' provisions to the Roman army, and being permitted to make war on the Sidicini.
The close of the First Samnite War was followed closely by the Latin War (340-338 B.C.). This war was brought about by the jealousy felt by the other Latin towns toward Rome. Rome had been abusing her position as the capital of the Latin League, and desired to acquire an acknowledged supremacy over Latium. The war was an effort on the part of the other Latin cities to restrain the too rapidly increasing power of Rome and to reëstablish the balance of power in Latium. In this war was seen the extraordinary spectacle of the Samnites appearing as allies of Rome. The Hernicans also aided the Romans, and the Sidicini and Campanians aided the Latins. The war resulted in the complete overthrow of the Latins; but the Romans showed great generosity and good judgment in their treatment of the conquered cities after the war, and thus did much toward binding the Latins to Rome for the future.
The main provisions of the peace agreements were as follows: Roman citizenships, in different degrees, were conferred upon the inhabitants of the various Latin towns, who were, however, forbidden to form any leagues among themselves or to hold diets; intermarriage and commerce between the different Latin towns were prohibited; the municipium such as the Latins had previously possessed was given to the citizens of Capua, Cumæ, Formiæ, Fundi, and Suessula; the Latin contingents in the Roman army were henceforth to be permitted to serve apart from the legions under their own officers; and the Latin public land, two thirds of that of Privernum, and the lands in the Falernian district of Campania were taken by Rome, as were also the lands of the principal families of Velitræ, who were compelled to emigrate beyond the Tiber.
Ten years of peace followed, and then came the second and greatest of the Samnite wars (327-304 B.C.). The Samnites were aided during part of the war by the Etruscans and the Hernicans, but at the end the Samnites were compelled to acknowledge the supremacy of Rome and give up their independence. The Hernicans were completely overthrown in 307 B.C., and were united to Rome on conditions very similar to those possessed by the Latins.
In the Third Samnite War (298-290 B.C.) the Romans were again victorious, although a league of Samnites, Etruscans, Gauls, and Umbrians was formed against them. The exact terms of the treaty of peace at the conclusion of this war are not recorded, but undoubtedly riveted Roman control still more strongly upon Samnium.
It was the final result of the Roman-Samnite wars which finally determined the question of the overlordship of Italy. Of all the numerous races of Italy, two and only two possessed the stamina which rendered them possible unifiers of the whole peninsula. Rome's defeat of Samnium left her without a rival in Italy and ready for contests with her later and greater rivals. The close of the Third Samnite War, however, did not end the resistance of the Samnites to Roman rule. Even down to the time of the contests of Marius and Sulla we find this race grasping every opportunity to strike a blow against Roman dominion.