The correct answer is Celtics, Etruscans, and Carthaginians.
The enemies the ancient Roman’s successfully battled were the Celtics, Etruscans, Carthaginians.
One thing that created fear and respect in the Roman Empire time was its powerful army. Historians say that in that epoch the Roman Empire conquered “one-third of the known world”. The only way they could do that was through a well trained and organized Army. The Roman Empire Army successfully battled the Celtics, Etruscans in the North, and Carthaginians in the South.
