A cataphract was a form of armored heavy cavalry that originated in Persia and was fielded in ancient warfare throughout Eurasia and Northern Africa.
The English word derives from the Greek κατάφρακτος kataphraktos (plural: κατάφρακτοι Kataphraktoi), literally meaning "armored" or "completely enclosed" (the prefix kata-/cata- implying "intense" or "completely"). Historically, the cataphract was a very heavily armored horseman, with both the rider and mount almost completely covered in scale armor, and typically wielding a kontos (lance) as his primary weapon.
Cataphracts served as the elite cavalry force for most empires and nations that fielded them, primarily used for charges to break through opposing heavy cavalry and infantry formations. Chronicled by many historians from the earliest days of antiquity up until the High Middle Ages, they may have influenced the later European knights, through contact with the Eastern Roman Empire.
Peoples and states deploying cataphracts at some point in their history included: the Scythians, Sarmatians, Alans, Parthians, Achaemenids, Sakas, Armenians, Seleucids, Attalid, Kingdom of Pontus, Greco-Bactrian Kingdom, Sassanids, Romans, Goths, Byzantines, Georgians, Chinese, Koreans, Jurchens, Mongols, and Songhai.
In Europe, the fashion for heavily armored Roman cavalry seems to have been a response to the Eastern campaigns of the Parthians and Sasanians in Anatolia, as well as numerous defeats at the hands of Iranian cataphracts across the steppes of Eurasia, most notably in the Battle of Carrhae (53 BC) in upper Mesopotamia. Traditionally, Roman cavalry was neither heavily-armored nor decisive in effect; the Roman equites corps comprised mainly lightly-armored horsemen bearing spears and swords and using light cavalry tactics to skirmish before and during battles, and then to pursue retreating enemies after a victory. The adoption of cataphract-like cavalry formations took hold among the late Roman army during the late 3rd and 4th centuries.