The fighting equipment and dress of the auxilia present a very complicated picture. Not only were there changes from time to time, but most of the units were differently equipped from the beginning. The only literary description which has survived is from the time of Hadrian about the army in the east.
The armoured cavalry (cataphractarii) was provided with armour, both horse and man being protected. The other kinds of cavalry had no protective armour. Some carried spears, some pikes, some lances, while others used only missiles. Some apparently carried oblong shields, some carried no shields at all.
Medium and heavy cavalry was often equipped with mail shirts, most striking of all the Sarmatian riders which were recruited into the army soon after the Dacian Wars. These Sarmatian units became an important arm in the late Roman army, when the value of heavy cavalry became more fully appreciated and it could almost be said that here was to be found the precursor of the medieval knight with his mail and hauberk.
Trajan’s column also features detailed examples of Eastern archers. These auxiliaries used short bows, a composite weapon made of bone and steel. They wore conical helmets and their bodies were protected by a mail shirt made of large scales. The quiver was carried high on the back so that the arrows could be plucked out from over the shoulder.
The auxilia never became so standardized in their equipment as the legions and it is probable that every regiment had its own distinctive features, which once established were jealously guarded.