Ab urbe condita
Titus Livius (Livy)
Livy. History of Rome, Volumes 1-2. Roberts, Canon, Rev, translator. London, New York: J. M. Dent and Sons; E. P. Dutton and Co., 1912.
These were called the First Class. The seniors were to defend the City, the juniors to serve in the field. The armour which they were to provide themselves with comprised helmet, round shield, greaves, and coat of mail, all of brass; these were to protect the person. Their offensive weapons were spear and sword.
To this class were joined two centuries of carpenters whose duty it was to work the engines of war; they were without arms. The Second Class consisted of those whose property amounted to between 75,000 and 100,000 lbs.
weight of copper; they were formed, seniors and juniors together, into twenty centuries. Their regulation arms were the same as those of the First Class, except that they had an oblong wooden shield instead of the round brazen one and no coat of mail.