Chancels (cancelli) are screens, often of great beauty and richness, set round an altar, or the choir, or tombs of saints. The original chancels were those which divided the choir from the nave, forming a line of demarcation between the clergy and the laity. Leo III erected a chancel of pure silver, and Stephen IV placed another of the same material round an altar. The second council of Tours enjoined the people not to stand near the altar among the clerks at vigils or mass, because that part of the church which is divided off by chancels is restricted to the use of the singing clerks. Gregory of Tours mentions a chancel in the chord of the apse in San Pancrazio near Rome, and at Santa Sophia, Constantinople. The chancel fenced the entrance to the sanctuary.
The chancel-screens round the choir were called, in Spain, rejas, and elsewhere pectorals, being a wall breast-high at which the faithful communicated and received the palms and ashes when they were distributed. It was identical with the peribolos which was introduced when the hours were first sung in choir during the 4th century. The solid and taller screen does not date earlier than the 12th century. Sometimes the chancels had a balustrade and columns, called regulars, placed at intervals; on these curtains were suspended, so as to resemble the Greek iconostasis; Gregory of Tours notices that they were embroidered and painted with sacred images in France. At certain times in the service these veil-like draperies were drawn back and again closed, unlike the modern custom of leaving the whole vista of the interior and the altar in full view; this utter change from the more ancient idea of seclusion of the sacred mysteries emanated from the Jesuits, contemporaneously with the introduction of the ceremony of benediction, and has resulted in a wholesale destruction of the rood-screens. The latter, which are the true representatives of the primitive chancels, marked the separation between the clergy and laity, and also symbolized the entrance to the Church triumphant. For this reason they were painted, as at Hexham, with figures of saints or with the sentences of the creed, or with the destruction of the dragon, or the Last Judgment. Two of these Screens, of open-work, of the time of Wren, exist at St. Peter's, Cornhill, and All-Hallows the Great, Thames Street, London; while beautiful specimens of lateral choir screens remain at Alby, at Paris, of the 14th century, at Chartres and Amiens, of the 15th century, and of the 13th century at Canterbury. The chancels mostly, however, have shrunk into the mere altar-rail round or in front of the altar, dividing, not as before, the nave from the choir, but the choir from the sanctuary.