A cataphract was a form of armored heavy cavalry used in ancient warfare by a number of peoples in Western Eurasia and the Eurasian Steppe.
The English word 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.
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 influenced the later European knights, via contact with the Byzantine Empire.
Peoples and states deploying cataphracts at some point in their history include: the Scythians, Sarmatians, Parthians, Achaemenids, Sakas, Armenians, Seleucids, Pergamenes, the Sassanids, the Romans, the Goths and the Byzantines. The term may sometimes be used to describe a Parthian chariot.