Equites cataphractarii Equites cataphractarii , or simply cataphractarii for short , were the most heavily - armoured type of cavalry in the Imperial Roman army and Late Roman army . The term derives from a Greek word , κατάφρακτος " kataphraktos " , meaning " covered over " or " completely covered " . Origins . Heavily armoured cataphract cavalry , usually armed with a long lance ( " contus " ) , were adopted by the Roman army to counter Parthian troops of this kind on the eastern frontier and similar Sarmatian cavalry in on the Danubian frontier . In distinction to both Parthian and Sarmatian cataphracts , who represented a wealthy feudal or tribal elite equipped for war , Roman cataphracts had no social dimension , being composed of professional soldiers like any other troop type of the Roman army . The Romans also used the terms " contarii " for lance - armed cavalry , and " clibanarii " for heavily - armoured cavalry . It is uncertain whether these terms were used interchangeably with ' cataphract ' , or whether they implied differences of equipment and role . Appearance and equipment . Modelled on the cataphracts of Parthia , they were armoured from neck - to - toe by a variety of armour types , probably including : scale armour ( " lorica squamata " ) , mail ( " lorica hamata " ) and laminar armour ( see manica ) . A number of descriptions indicate that helmets with visors shaped like human faces were worn . However , a graffito from the Roman frontier fortress of Dura Europos shows a cataphract wearing a conical helmet with a face - covering mail aventail . They were normally armed with a " contus " , a long lance held in both hands . However , the name of one one unit , " equites sagitarii clibanarii " , implies that these troops carried bows instead of , or in addition to , the " contus " . As a secondary weapon they were armed with swords ( " spatha e " ) . In some cases , their horses were covered in scale armour also . Two iron and copper - alloy scale horse armours , usually called ' trappers ' or ' bards ' , still attached to fabric backings were discovered in a 3rd - century context at Dura Europos . The best description of these cavalry to survive , was made by the Late Roman historian Ammianus Marcellinus : “ . . . among these were scattered cavalry with cuirasses ( " cataphracti equites " ) , whom the Persians call " clibanarii , " protected by coverings of iron breast - plates , and girdled with belts of iron , so that you would fancy them statues polished by the hand of Praxiteles , rather than men . And the light circular plates of iron which surrounded their bodies , and covered all their limbs , were so well fitted to all their motions , that in whatever direction they had occasion to move , the joints of their iron clothing adapted themselves equally to any position . ” Ammianus ( 16 . 10 . 8 ) Battlefield role and limitations . Heavily armoured , mounted on armoured horses and wielding a lance so long it normally required both hands , the " cataphractarii " were specialised for shock action . They have been likened to the tank of the Ancient World . Their armour enabled them to attack enemy infantry and cavalry with confidence and virtually ignore missile fire . However , the armour was heavy and both soldier and mount could tire quickly in battle , and therefore become vulnerable to counterattack . In particular , horse armour prevented the horse from cooling itself effectively by sweating ; therefore heat exhaustion could be a great problem , especially in hot climates . Cataphracts needed to maintain a close and ordered formation to be effective and their flanks were particularly vulnerable to attack . If their formation became broken , individual cataphracts could be attacked by lighter - armed troops with relative ease . At the Battle of Turin the emperor Constantine I destroyed a numerous force of enemy cataphracts ; he manoeuvred his army in such a way that his more lightly armoured and mobile cavalry were able to charge in on their exposed flanks . Constantine ' s cavalry were equipped with iron - tipped clubs , ideal weapons for dealing with heavily armoured foes . Development . It was apparently from the time of the emperor Trajan ( ruled AD 97 - 117 ) that the first regular formations of Roman " cataphractarii " appear in the record . These were all in the auxiliary , not the legion ary corps . The earliest known units of " equites cataphractarii " , both recorded in the early 2nd century , are the auxiliary cavalry regiments , " Ala I Gallorum et Pannoniorum cataphractaria " , stationed in Moesia Inferior and the " Ala I Ulpia contariorum " , stationed in neighbouring Pannonia Inferior . The deployment of these on the Danube front , rather than in the East , implies that initially the " cataphractarii " were aimed at countering the Sarmatian , rather than the Parthian threat . " Cataphractarii " regiments apparently remained few in number in the army of the Principate ( to AD 284 ) . They became more numerous in the Late Roman army , especially in the East . However , it should be noted that a number of the " eastern " units have Gaulish names ( including the Biturigenses and Ambianenses ) , indicating their western origins . Nineteen units are recorded in the " Notitia Dignitatum " , of which one was an elite " schola " regiment of imperial horse guards . All but two of the rest belonged to the " comitatus " ( field armies ) , with a minority rated as elite " palatini " troops . There was just one regiment of cataphract horse archers .