A centurion was promoted for being an exemplary soldier and was then expected to become a strict commander of his subordinates, to lead his troops by example, and coordinate his century's actions.
A centurion's symbol of office was the vine staff, with which they disciplined even Roman citizens, who were otherwise legally protected from corporal punishment by the Porcian laws.
Centurions were held personally responsible for the training and discipline of the legionaries under their command, and they had a reputation for dealing out harsh punishment.
Tacitus tells a story in The Annals of a centurion known as "Cedo Alteram", which roughly translates to "Fetch Me Another".
For example, Julius Caesar's reward for a centurion who had greatly pleased him was to advance him eight grades.
Note that the Primi Ordines of the first cohors were senior to every centurio except for their Primus Pilus and the Pili Priori of the other first centuries.
According to a 5th century text on the Roman military, a centurion was required to have numerous elite traits: The centurion in the infantry is chosen for his size, strength and dexterity in throwing his missile weapons and for his skill in the use of his sword and shield; in short for his expertness in all the exercises.
He is to be vigilant, temperate, active and readier to execute the orders he receives than to talk; Strict in exercising and keeping up proper discipline among his soldiers, in obliging them to appear clean and well-dressed and to have their weapons constantly rubbed and bright.Centurions had to be at least 30 years of age, literate (to read written orders), have letters of recommendation, and have at least several years of military service.
As a commander, a centurion had to be able to maintain his troops’ morale in peace and inspire his men in battle.
In the Gospel of Luke, the centurion concerned had a good relationship with the elders of the local Jewish population and had funded the development of the synagogue in Capernaum, and when he heard that Jesus was in the locality, he asked the Jewish elders to request healing for his servant.
In both the Gospels of Mark[20] and Matthew,[21] the centurion who is present at the Crucifixion said that Jesus was "God's Son".
The apostle Simon Peter is told in a vision to visit Cornelius, a Gentile, with whom association was not permitted under Jewish law.
Another centurion, Julius, is given custody of the apostle Paul for his journey from Caesarea to Rome in Acts 27.