The Roman army was the largest and meanest fighting force in the ancient world.
One of the main reasons Rome became so powerful was because of the strength of its army. It conquered a vast empire that stretched from Britain all the way to the Middle East. The army was very advanced for its time. The soldiers were the best trained, they had the best weapons and the best armour. Being a soldier was a serious business.
When the Romans invaded Britain, their army was so good that it took on armies 10 times its size and won!