In the tenth and eleventh centuries, the period of their greatest power, the Byzantine horsemen were the best paid and best equipped and organized military force of their time.

During the rule of Emperor Nicephoros II (963-9), Byzantium, free from the Bulgar threat, undertook military enterprises in Asia Minor. Cyprus and Syria were conquered, and the Arabs taken on in Palestine. The state treasury grew richer. Nicephoros formed units modelled on the late Roman heavy cavalry (clibanarii) and the extra-heavy (klibanophoroi). This name derived from the klibanion, a corselet used by the Byzantine riders; its name in turn came from the Latin clibanarius (heavily armoured horseman). Because their equipment was very expensive, the klibanophoroi probably only existed in the guard (tagmata).

On the battlefield, the klibanophoroi used a wedge formation, with 20 men in the first line, 24 in the second, and four more in each following line. The last, twelfth, line had 64 men, and the whole unit 504. A formation more frequently used had 10 lines and 384 men. Approximately every fourth and fifth man was armed with a bow instead of a lance, and positioned slightly to the rear inside the wedge. There were probably three units of klibanophoroi in the tagmata, totalling between 1,000 and 1,500 men. Every unit bore its own pennant on lances, and had vestments of a distinctive colour.

The klibanophoroi were armed with a lance (kontos), about 4 m/13 ft long, which had been adopted from the Sarmatians and Alans, and a sword (spathion, from the Latin spatha) with a 90 cm/35 in blade. The first four ranks of klibanophoroi also carried several short darts (marzabarboulon) in a leather case hanging from the saddle. Byzantine cavalry used three basic types of protection: mail, scale and lamellar armour, the last being the most often used. The lamellae were mostly of iron, although leather and horn were used too. Riders also wore a wide-skirted, knee-length topcoat with short sleeves (epilorikion), made of padded and quilted cotton, leather and felt, at least 2 cm/1 in thick and worn over the corselet. The lower parts of the legs were protected by iron graves (podopsella), and the forearms with splint armour vambraces (chiropsella). Horse-armour was made of horn or iron lamellae or mail, but multi-layered felt covering is also mentioned. Headgear was of the same materials, and metal chamfrons were possibly used as well.

After defeat at the hands of the Saljuqs at Manzikert, in 1071, the klibanophoroi ceased to exist.