The cataphractaries (from the Greek κατάφρακτος, kataphractos) were originally Sarmatian or Alan heavy cavalry units. The army of the Early Roman Empire (and the army of the Byzantine Empire) also used this type of unit. The armor that distinguishes its knights is called a cataphract.
Cataphract
Of Sarmatian origin, they mark a change of orientation compared to the type of combat that preceded it. Traditionally the steppe peoples around the Black Sea were above all horse archers (Scythian, Parthian). After intense archery preparation (in successive passes) the noble component of the cavalry (protected by scale armor) could charge to finalize the victory. The principle of use of cataphracts is different, the archers' passes are used to prepare the charge of the heavy cavalry. The main weapon is no longer the light cavalry armed with the bow, but the heavy cavalry. Another fundamental difference, the heavy cavalry was armed with long lances (4 meters to 4 meters 50) that the rider had to hold with 2 hands (a weapon of this size requires 2 hands or one hand and a support fixed on a rigid breastplate ( the faucre of the Middle Ages)). This novelty gave the rider enough reach to hit an opponent armed with a spear.
Defensive armament
Defensively, the cataphract wore a scaly brooch or scale armor called a cataphract. He usually wore a composite helmet, usually made from 4 to 6 riveted blades. However, there are helmets made up of many more blades (10, 15, etc.) and helmets where the blades were laced. However, this bodily defense was not mandatory. There are representations of cataphract charging without any defence. It must, however, have been very exceptional. No shield was carried by the cataphracts, the hands being taken by the spear.
Offensive armament
The cataphracts were armed with a long sword (about 80 cm) and especially the contus. The contus (Latin:contus, Greek:kontós Frenchified in contos) was a spear of 4 meters to 4 meters 50. It was the distinctive mark of the cataphract. Other riders wore the cataphract and not all the cataphracts wore tusks, but all cataphracts wore the contus. Some historians have proposed changing the name of cataphract to another name such as contusii (lancer) closer to Roman names. Cataphracts often carried a dagger in addition to their basic armament.
Saddle
The saddle was used by cataphracts for at least part of their existence. It was not the "horned saddle" of Gallic origin and used by the Romans, and it was not the stirrup saddle (did not yet exist at the time).
As a result, for lack of a stable support, the handling of the spear became "tricky".
Derived unit
Without being called cataphract, some units have more or less commonly adopted the contus. They were corps of Greek cavalry, from poor towns that could not afford the mercenaries and hoplites used by the richer cities. Mainly Macedonia, which for the same reasons developed the Macedonian phalanx. Several representations of Alexander the Great in contusii have come down to us.
In general, peoples desiring contusii hired Sarmatian or Alani mercenaries or made agreements with Sarmatian or Alani troops or peoples (the “Foederatii” system). They were mainly, if not exclusively, Greek and Roman cities at first, then by the "barbarians" during the invasions (Visigoths, Ostrogoths, Huns, Vandals, etc.)
Tactics
Cataphract units were an essential part of Byzantine military tactics. The contusii were a breaking weapon. After a preparation of archery or infantry, they charged like the knights of the High Middle Ages, broke the opposing ranks and tried to disperse them.
By combining with the Roman or "barbarian" armies, they had above all a role of breaking the front, to the benefit of the infantry.
Technical
As shown in the diagram, the contus held the back of his spear with the right hand, the front of the spear with the left hand and supported it on the thigh to stabilize it. The rider kept the sword from swinging by jamming it with his left leg. Even so, aiming at a target was difficult, especially since due to its length, the contus bends under its own weight. After the initial charge, the cataphract used a kind of fencing by wielding his spear with 2 hands.
Broadcast
From the reign of Hadrian (Publius Aelius Hadrianus reigned from 117 to 138), Rome built up a cavalry of cataphracts. For this she brought in Alans (as part of the foederati) and armed them in clibanarii. From this period date strange representations of Roman clibanarii, wearing a cuirass of scales completed by arm and leg defenses composed of segments of cylinders fitted into each other (Parthian origin but also used by Roman gladiators) and by a face helmet whose timbre was one-piece.
Subsequently the Roman Empire installed other cataphract troops on its territory. Always as federates, and mainly in the East (Byzantium).
Around 370, the Huns made their appearance in the Black Sea steppes. They spread out to the west, repelling Sarmatians, Alans and Germans. These crossed the limes (border) of Gaul. Unable to defeat them militarily, the Empire installed them as federates, but had no real control over them. The Huns maintaining their pressure, other groups in turn crossed the border, even as their predecessors were agitated, as the governors of each region took more and more freedom from the central power and as the people threatened to to revolt (monetary crisis, tax problem, weak central power and corrupt local power, desire for independence never having died out since Caesar and weak army). Rome reacted by trying to reinforce its army the only way it could. Through alliances and the federated system (installation of foreign troops, who provided military service in exchange for semi-independence). Through all these means, Alans and Sarmatian troops were established throughout Gaul, in Roman England, and even in Italy after the first incursions of the Lombards. When Rome finally lost its footing, most of the “Barbarian” troops present in the Empire used cataphract troops of Alans and Sarmatian origin. For example, some historians attribute to a Sarmato-Alain component the origin of the Frankish cavalry. The Vandal kings who conquered the Maghreb, then Spain (when Byzantium drove them out of the Maghreb) gave themselves the title of king of the Vandals and the Alans. When the Lombards, worried by the presence of their neighbor and "ally" Avars definitively invaded Lombardy, they were accompanied by contingents of other Germanic and Alans peoples (who feared to stay in the vicinity of the Avars). Byzantium federated Alans and Sarmatians since Hadrian.
Oddly, the Avars are rarely cited as cataphracts. Yet they used heavy cavalry, armed with the contus, the longsword and the bow. This is not due to differences in armament with conventional cataphracts. The difference between the Avar horsemen and the heavy horsemen of the other Euro-Asian peoples of the time is much greater. It is due to the fact that the Avars (who arrived in Europe around 450) brought the stirrup with them (already known in Asia for at least a century).