Legions is a military term that has been used since ancient times. In early Rome the ‘legion’ was a levy of citizens marching to war, or, in other words, a citizen army. As conquests grew, Rome needed more men and Legio came to denote a force of four to six thousand heavy infantry supported by a cavalry contingent and light infantry. The light infantry were armed with darts, slings and other missile weapons. The military system of the legions enabled the Romans to conquer and rule the ancient world. This was the way the men of the legions fought: they were arranged in three lines, the Hastati in front, followed by Principles and lastly by the Triarii. The Hastate engaged the enemy but, if beaten, retired, leaving the Principles, highly experienced troops, to continue the battle. The Triarii knelt and positioned their spears to form a defensive line. Each legion had its proud traditions. Renowned was the 10th – the favourite of Julius Caesar. About the period 200 B.C. every Roman from the age of seventeen to forty-six was liable to be called to serve as a soldier in one of the legions.