Hope this helps:
At about 500 BC, the Latin language was only spoken in the City of Rome itself and the surrounding countryside. Today 700 million people spread across every continent of the world speak a language that is derived from Latin. How did this language group spread so far? The answer lies in the military conquests of the City of Rome in the First Millennium BC.
The Roman Empire’s conquest of the Mediterranean and Western Europe, and the stories of Roman Emperors such as Julius Caesar and Octavian are well known. But what is perhaps more impressive is the story of how the Early Roman Republic, confined to a small area of central Italy, and surrounded by many larger, aggressive tribes, was able to dominate the Italian Peninsula. This domination was achieved through a mix of military conquests, colonization, and strategic alliances. Eventually as Rome’s military power grew, those cities that “allied” with Rome became dependent upon her. The map above charts the progress of Rome’s ascendency in the Italian Peninsula, the colors represent different time periods where Rome’s authority was felt, either directly or through alliances.
In the north, Rome came into conflict with the Etruscans, who had at one time dominated the area around Rome. To the East, the Romans were involved in three wars with the Samnites.
Rome's conquest of mainland Italy culminated in the Pyrrhic War. By the beginning of the Third Century BC, the Greeks, who had began colonizing Southern Italy in the 8th Century BC, began to grow wary of the growing influence of Rome. The Greeks invited King Pyrrhus of Epirus to help them in their conflict with Rome. King Pyhrrus was an esteemed general and cousin of Alexander the Great, he was able to defeat the Romans in a number of battles, but at such a cost in manpower and resources that he was quoted as saying:
"If we are victorious in one more battle with the Romans, we shall be utterly ruined." (source)
King Pyrrhus was taken aback by the resilience of Rome, it seemed that they had an endless supply of soldier, described by Plutarch "..as from a fountain continually flowing out of the city".(source)Eventually King Pyrrhus sought a compromise with Rome, but they refused any peace negotiations whilst he remained on Italian soil. King Pyrrhus's final departure from Italy marked the end of any real resistance to Roman rule from the Greek cities of Italy. In modern English, the term "Pyrrhic Victory" has come to mean a victory that comes at a devastating cost to the victor.