The Cataphractarii were the tanks of late antiquity. Like their eastern equivalent, the Clibanarii, they were heavily armoured and also made use of the contus. The contus was a long cavalry lance of between 3 and 5 meters. It should be noted that medieval lances only measured about 2.50 to 3 meters in length. Due the extreme length the contus had to be used with both hands and thus the Cataphractarii didn't use shields, or if so only very small shields strapped to the upper arm.
To be able to use their weapons while stirring the horses with their knees, the Cataphractarii probably had to undergo long and hard training. While this made them an excellent weapon on the battlefield it also meant losses were only hard to replace. Thus the Cataphractarii werer highly likely only to be used in extreme circumstances. The first time units of Cataphractarii appear in Roman records was as early as the early second century A.D. as part of the auxiliary. Ala I Gallorum et Pannoniorum was stationed in the province of Moesia Inferior while Ala I Ulpia Contariorum was stationed in Pannonia inferior. In the west the Cataphractarii more or less disappeared together with Roman rule and it took a few hundred years till such heavily armoured cavalry roamed the battlefields again in the form of the high medieval knight.