Mirror armour (Old Russian Зерцало Zertsalo which means a "mirror", Kazakh: Шар-айна Shar-ayna were Kazakh: айна ayna means a "mirror" too), sometimes referred to as disc armour or Chahar-Ainé (Persian چهاﺮآﻳنه ) where "آﻳنه " means mirror and " چهاﺮ" is the number "four". It literally translates to "four mirrors" which is a reflection of how these pieces looked, which resembles four rivetted metal discs or oblong mirrors. It is a kind of oriental partial plate armour which was developed initially from round metal mirrors (a kind of rondel) worn over other armour (usually over mail) as enforcement. Metal mirrors in this armour were considered not only as protection from cold steel and arrows, but also from supernatural influence. It was believed that mirrors could reflect the evil eye, so they were polished and worn over other armour.
Early mirror armour consisted of a round mirror attached to the body with a few leather laces (similar to the Roman phaelerae of Romulus' time).
Late mirror armour took the form of a mirror cuirass, helmet, greaves, and bracers worn with mail.
There were two alternative constructions of mirror cuirass:
* with discs - two large round mirrors surrounded by smaller mirror plates
* without discs - typically having four mirror plates - frontplate, backplate, and two sideplates joined by hinges or laces, similar in construction to the Japanese Yukinoshita Dô/Sendai Dô. The main difference from Yukinoshita Dô/Sendai Dô was that the right plate in Yukinoshita Dô/Sendai Dô consisted of two overlapping plates. Another difference is that the mirror cuirass may have three or five plates, instead of four, and open from the front.
Early types of this armour were known in the Middle East, Central Asia, India, Russia, Siberia (where it was worn by Siberian natives before the Russian conquest), Mongolia, Indochina and China.
Later types of this armour were known in the Middle East, Central Asia, India, and Russia. The mirror cuirass with discs was popular in Turkey and Russia, while that without discs was popular in Persia, Central Asia and India.
In India, there was a popular form of brigandine with a few mirror plates riveted to it.
According to Bobrov round metal mirrors worn by Mongolian warriors as armour reinforcement are shown in Persian miniatures of 13c. This is verified by archaeological finds in Central Asia and the Far East. This kind of armour prevailed in Central Asia during 15-17c, and could be worn over any armour including brigandines, lamellar armour, chainmail and even plated mail. In 16c in Persia mirror plates become much larger and changed their shape to rectangular in order to improve body protection. This improved mirror armour gradually spread during 16-17c to Central Asia and North India. Further improvements were made during the 1640s when mirror plates evolved into mirror cuirass, which sometimes had additional mirror plates used as pauldrons for protection of the shoulder laces. Besides separate mirror plates laced as reinforcement to other armours there were small mirrors that were sewn or riveted to brigandine. Brigandines with such integral reinforcements were very popular at the end of 15c, but their use had practically been abandoned by the end of 17c.