Mitres were established headgear for Christian bishops by the 11th century; they were also worn by the Pope (Bishop of Rome) and high-ranking abbots. By the 12th century they were usually made in white linen or silk, and often had figurative scenes showing saints. The style of this mitre falls within the final phase of this ornament's development, from the smaller and simpler medieval mitre into the more exaggerated 17th-century highly peaked version (similar to the version worn today). Traditionally, mitres fell into three classes: the mitra pretiosa, decorated with precious stones; the mitra aurifirigiata, embroidered sometimes with gold; and the mitra simplex which was plain.
In this case, the embroidered images refer to Christian iconography: the Virgin Mary, Saints Augustine (an early Father of the Church), Peter, Paul, Barbara and Leonard. All but St Leonard (from Limoges in central France) were widely venerated during the Middle Ages. He was less well-known, but had a following in England, France and Germany where he was considered the patron of prisoners. The choice of him as an appropriate saint for this mitre suggests that it was made for use in a church in one of these countries, probably France. An inscription in French inside the mitre states that it was made in 1592 and repaired in 1766.