Who did the Romans defeat to take full control of the Italian peninsula?

Answer 1

The Roman conquest of Italy was a process that took over 230 years. Rome was still a republic city state during this period of gradual conquest. Wars beginning around 500 BC, saw Rome and an alliance of Latin city states conquer hostile Italic cities in areas closest to Rome. The conquest of the entire Italian peninsula was halted when tribes of peoples from Gaul, an area near the size of present day France sacked Rome. These tribes, also known as Celts, withdrew from the areas surrounding Rome by accepting a huge sum of monies from the citizens of Rome. Rome realized this was only going to be a temporary peace. Thus, during a 50 year period, Roman armies were able to drive the Gauls back. This ended the threat posed by these tribes. The next Roman objective was to make certain that their former allies, the Latin city states, were subdued and came under the rule of Rome. This secured the the central part of the Italian peninsula for Rome. Prior to the establishment of Rome on the river Tiber, the original peoples of Italy, were the Etruscans and the Samnites.

Their influence and whatever power they had were abolished by Rome around 295 BC. In 270 BC, Rome conquered the Greek colonies in southern Italy.