Following Marius' reforms in 107-104 BCE, the centurion given command of the right centuria of the maniple was known as the prior centurio, whilst he on the left wing was called the posterior. Of all these centurions, the most senior was the primus pilus, who also had a seat on the military council. Two centuriae made up a maniple and the most experienced centurion took the right wing. The legion in this period was divided into 30 manipuli with a total of 60 centuriae units each commanded by a centurion who appointed his own junior officer ( optio). Polybius describes the army units of the mid-2nd century BCE where there were 4,000 men to a legion that now included light skirmishers. Therefore, a 4th century BCE legion ( legio) had 150 centurions.Ĭenturions were expected to lead by example & display the greatest courage on the battlefield. In the 4th century BCE, further reforms reshaped the manipuli into more flexible military units deployed in three lines of troops ( acies triplex), so that the number of infantry commanded by a centurion was reduced to 30. Over time the organization of army units evolved, and by the late 6th century BCE, the army had two legions, each composed of 3,000 heavy hoplite infantry, 1,200 light infantry, and 300 cavalrymen. 579-534 BCE), the rank being given to the bravest soldiers in battle. According to Dionysius of Halicarnassus, the centurion rank had Etruscan origins and was incorporated into the Roman army by the Etruscan king of Rome Servius Tullius (r. According to Roman tradition, the existence of centurion rank went right back to the first armies of Rome in the mid-8th century BCE which, led by the legendary Romulus, had 3,000 men and 30 centurions, each commanding a 100-man infantry group known as a manipulus, which also had its own standard or signa.