A cataphract was a form of armored heavy cavalry utilised in ancient warfare by a number of peoples in Western Eurasia and the Eurasian Steppe.
The word in English is derived from the Greek: κατάφρακτος Kataphraktos (plural: κατάφρακτοι Kataphraktoi), literally meaning "armored" or "completely enclosed". Historically, the cataphract was a very heavily armored horseman, with both the rider and steed draped from head to toe in scale armor, while typically wielding a kontos or lance as their weapon.
".. But no sooner had the first light of day appeared, than the glittering coats of mail, girt with bands of steel, and the gleaming cuirasses, seen from afar, showed that the king's forces were at hand." Ammianus Marcellinus, late Roman historian and soldier, describing the sight of Persian cataphracts approaching Roman infantry in Asia Minor, circa fourth century.
Cataphracts served as either the elite cavalry or assault force for most empires and nations that fielded them, primarily used for impetuous charges to break through infantry formations. Chronicled by many historians from the earliest days of Antiquity up until the High Middle Ages, they are believed to have given rise in part or wholly to the Age of Feudalism in Europe and the later European equivalents of Knights and Paladins, via contact with the Byzantine Empire.
Notable folks and states deploying cataphracts at some point in their history include: the Scythians, Sarmatians, Parthian dynasties, Achaemenid Empire, Sakas, Armenia, Seleucids, Pergamenes, Empire of Goguryeo, the Sassanid Empire, the Roman Empire and the Byzantine Empire.
In the West, the fashion for heavily armored Roman cavalry seems to have been a response to the Eastern campaigns of the Parthians and Sassanids in the region referred to as Asia Minor, as well as numerous defeats at the hands of cataphracts across the steppes of Eurasia, the most notable of which is the Battle of Carrhae. Traditionally, Roman cavalry was neither heavily armored nor all that effective; the Roman Equites corps were composed mainly of lightly armored horsemen bearing spears and swords to chase down stragglers and to rout enemies. The adoption of cataphract-like cavalry formations took hold amongst the late Roman army during the late 3rd and 4th centuries. The Emperor Gallienus Augustus (253–268 AD) and his general and would-be usurper Aureolus bear much of the responsibility for the institution of Roman cataphract contingents in the Late Roman army.
Read more about Cataphract: Etymology, Indo-Iranian Origins, Spread To Central Asia and The Near East, Exposure To Western Civilization, Appearance and Equipment, Tactics and Deployment, Later History and Usage in The Early Middle Ages, Related Cavalry