Except for the brief interruption of the Gallic disaster, Roman expansion in Italy was almost uninterrupted in the period 400-265 B.C.E. Among its first victims was the Etruscan city, Veii, which Rome attacked on its own without any help from its Latin allies. Therefore, when Veii fell, Rome gained a large amount of land for itself without having to share it with the Latins. It gave much of this land to poor Roman citizens, which set into motion a recurring pattern that would eventually help Rome conquer Italy. Since more Romans had land, they could now afford the arms and armor to serve in the army. This gave Rome a larger army, which meant it could conquer more land, distribute it to more citizens, further increase its army, and so on.
Two other Roman practices came out of this cycle and led back into it to help Rome in its path of conquest. One was the practice of founding colonies to gain and secure their hold on a region. The other was the building of roads to help Roman armies move more quickly and easily than their enemies to threatened areas.
After the fall of Veii, Rome would sweep from one conquest to another, first crushing a revolt by its Latin allies, next conquering the Samnites and Campania in two hard-fought wars, and finally defeating the Hellenistic army of Pyrrhus of Epirus to bring the Greeks in Southern Italy under control. And with each conquest, more Romans would get land, buy arms and armor, and increase Rome's army, conquests, etc.
Rome's recovery from the Gallic invasion was swift. It quickly put down a revolt of the Latin allies and then replaced the Latin League with separate treaties between Rome and each Latin state, thus tying each city to Rome alone.
Rome's victory now got it involved in affairs in Campania. When southern hill tribes, known as Samnites, started threatening the rich cities of Campania, they looked to Rome for help. This touched off the Second Samnite War (326-304 B.C.E.). The Romans quickly ran into serious problems fighting the Samnites in the hills. Up to this point they had used the Greek style phalanx as their main tactical unit. This was ill suited to fighting in mountain passes. An entire Roman army was even captured in a pass known as the Caudine Forks. The Roman, being ever adaptable, copied their Samnite enemies who used more open and flexible formations with soldiers equipped with throwing javelins, swords, and lighter armor. These formations, called maniples, were arranged in a checkerboard fashion that allowed the Romans to advance fresh troops into a battle and withdraw tired ones from it. The new Roman legions might bend, but they rarely broke. Not only did they win the Samnite wars and Italy for Rome, but, with a few modifications, they would eventually conquer the entire Mediterranean.
The Second Samnite War was a long, hard fought affair that saw Rome initiate two other policies: road building and colonies. In 3l2 B.C.E., the Romans built the first of their military roads, the Appian Way, to move troops quickly in times of war. However, the Appian Way and other such roads would also be highways of trade and commerce in peacetime. Eventually, there would be 5l,000 miles of paved roads linking different parts of the Roman Empire together. Rome also founded colonies to cut Samnite supply lines and communications and established firm Roman control in the area.
Because of their military reforms, roads, and colonies, the Romans finally defeated the Samnites in 304 B.C.E. They were lenient with their defeated enemies, but this allowed the Samnites to start a third war (298-290 B.C.E.). However, the Roman system of maniples, roads, and military colonies on their enemies' borders gradually strangled the Samnites into submission once again.
Except for Cisalpine Gaul, only the Greeks in the very south were now free of Roman control. Growing increasingly nervous about Rome's intentions, the most powerful of these cities, Tarentum, went to war with Rome in 280 B.C.E. Tarentum had great wealth, but little fighting spirit. Therefore, it had the unusual habit of hiring foreign kings to fight its wars. In this case, it called in Pyrrhus, a cousin of Alexander the Great and ruler of the kingdom of Epirus, north of Greece. For the first time, the Romans were up against a military system more sophisticated than their own, using the dreaded Macedonian phalanx and war elephants. The more flexible maniples fought bravely on the plains of Heraclea and Ausculum, but were beaten. However, Pyrrhus' victories were so costly compared to what he gained that even today we refer to such victories as "pyrrhic". In the face of such defeats Roman perseverance shone forth, the Senate refusing to make peace until every last Macedonian had left Italian soil. In 275 B.C.E., the Romans beat the Macedonian phalanx by luring it onto hilly or broken ground. Pyrrhus beat a hasty retreat back to Epirus, and Italy now belonged to Rome.
Conquering a region is one thing. Ruling it is another. And it was here that the Romans showed their true greatness. Instead of ruling like tyrants, they offered various grades of Roman citizenship and the chance to share the benefits of Roman rule with the Italians in return for their loyalty. Newly conquered cities were made allies that had trade and marriage privileges with Romans. As a city gradually proved its loyalty to Rome, it would receive the status of partial, or Latin, citizenship. Eventually, a city proving its loyalty over a long period of time would be granted full Roman citizenship. All of Rome's subjects were expected to supply troops for war and give up their independent foreign policies. However, Rome did let them keep their local governments and customs, but they tended to resemble those of the Romans more and more with the passage of time. Rome also kept building roads and founding colonies. Colonies with Latin citizenship were especially popular, since they were a bit more independent than full Roman colonies, while still providing Rome with troops.
The value of Rome's system for governing Italy should be obvious. Instead of constantly worrying about rebellions, it had a reliable source of loyal manpower and resources to help increase its power. The greatest test of this was when Hannibal tried to conquer Italy, thinking the Italians would flock to his standard against the Roman tyrant. Instead, most of Italy, especially the parts under Roman rule the longest, stood fast by Rome, despite the fact that Hannibal's army was in Italy for sixteen years. The Romans would continue this policy of offering citizenship to their subjects. In fact, in 2l2 A.D., the Roman emperor, Caracalla, completed this process by offering Roman citizenship to all freeborn men in the empire.
By 265 B.C.E., Rome had a strong stable government and Italy firmly under its control, secured by the lure of citizenship, a growing network of military roads and colonies, and probably the best-trained and most efficient army of its day. Given such a large, well organized, and energetic power, it should come as no surprise that Rome was ready for further expansion. Across the narrow strait of water to the south beckoned Sicily. Expansion there would mean war with a great naval power, Carthage, and the start of the road to empire.