The Roman Empire lasted approximately 2000 years. During that time, the Roman army became a potent weapon for expanding the empire and keeping the peace. It was also used by various ambitious soldiers and politicians of the empire to take control during many civil wars and infighting over the years.
Given the longevity of the Roman empire, it’s safe to say that the Roman army was probably one of the first professional armed forces. Much of the command structure and basic day to day running of the army has similarities to modern day armies. Indeed, the Roman army was the precursor for many modern day armies.
The Roman army had various ranks and special units. It also adapted and changed over the centuries. For instance one such special unit was known as the Praetorian Guard. This unit was a specialized unit that protected the Emperor or even a general in the field. They were specially selected as their loyalty to the Emperor was vital if the Guard was to be effective. The Praetorian Guard would have a special uniform and would be considered an elite force. Other special units might be cavalry units or those that specialized in certain weapons.
Outside of the special forces, the rank and file of the Roman army were known as legions. Legionnaires were the foot soldiers or the grunts. They had a commanding officer, known as a Centurion.
The typical outfit or costume of a Roman soldier would also vary depending on the location in which they were posted. For instance, the outfit that a soldier would wear in Ancient Briton would differ from that in the Middle East. With this said, everyone pretty much recognizes the standard Roman soldier costume based on movies, TV shows and other media.
It consists of a helmet. The standard soldier would have a fairly plain helmet, that protected the head and in some cases the face. The higher in rank you became in the Roman army, the more elaborate your helmet became (whole uniform in general). The helmet that everyone identifies with is the one with the large plume of red running down the center of the helmet.
(It’s actually a Spartan inspired costume but you could pass it off as a Roman soldier costume…maybe one that is for some place warm like Egypt or Carthage)
Along with the helmet, a soldier might wear an under tunic. On the tunic he would wear various pieces of armor. The first piece of armor to consider would be the breastplate. He would also wear shoulder arm and shin guards. Some soldiers would wear wrist guards too. A centurion would wear a bracelet on his wrist denoting his rank. Again, based on his rank or duties, the soldier might wear a cape. All soldiers would have their own sword, spear and shield.
A Centurion was the commanding officer of a legion. The term centurion is a general term for officer and the centurion would be a senior officer like a colonel down to a captain in today’s army. The captain would control a smaller number of men and would have different duties to a colonel, who would have more administrative duties to carry out.
Thus a centurion costume could be quite unique in terms of decorative patterns on the breastplate to color of plume on his helmet. The plume could go across the helmet rather than down the middle as the standard issue soldier might wear. Many of the leading officers of the Roman army hailed from the Roman aristocracy, so they also added their own touches to their armor and dress.