The vestment alb has its origin in six different garments: The chiton, the kolobus, the tunica, the colobium, the tunica talaris and the girdle.
The chiton was a rectangular piece of linen folded across the body and pinned together at the shoulders. Eventually, the open side was sewn together, so that the garment became a cloth tube. The wearer would step into it and pin it at the shoulders. Young men wore short chitons, while the older men wore a longer version that reached their feet.
During the time of republican Rome, the chiton got renamed again, this time the tunica. If the wearer was about to do something strenuous, such as fight, he would gird up his tunica to give his legs freedom of movement. A tunic that was long enough to reach the feet was called a tunica talaris.
Around the fourth century B.C., the kolobus came into use. Again, it was a fabric tube, but instead of being pinned at the shoulders, it was sewn together, leaving enough space for the head and arms. Again, it was girded about the waist.
The Romans also adopted the Greeks’ kolobus and renamed it the colobium. It was still a fabric tube with openings for the head and shoulders, but the colobium was wider at the shoulders than at the waist so that sleeves – albeit short – were created.
The girdle held all of these garments in place around the waist. It was considered uncouth to appear in public without a girdle. Everyone wore one, from the lowly peasant to the emperor. It was usually a narrow band of material that was usually decorated with gold or semi-precious stones, although 0rdinary folk wore girdles made of cord, linen or leather.
During the first century A.D., because the tunica was universally white, it was called the tunica alba, a forerunner of the term vestment alb. During the second and third centuries, men in the upper classes started wearing the long tunica talaris, also called a long colobium. People started making them with long sleeves.
During the fourth century A.D., Sylvester, Bishop of Rome, decreed that deacons should wear a clean tunica talaris when assisting at the altar. The word alb was used for the first time in a canon of the Council of Carthage stating deacons should only wear them when officiating at the altar. Bishops and priests could still wear the alb for everyday dress.
By the sixth century, the vestment alb was firmly established along
with the girdle. Eventually deacons wore a dalmatic or stole over their
albs, while priests would cover their alb with a chasuble.