In the Early Church, the sanctuary was connected directly to the nave. The choir was simply the east part of the nave, and was fenced off by a screen or low railing, called cancelli, which is where the English word chancel comes from. The development of the architectural feature known as the choir is the result of the liturgical development brought about by the end of persecutions under Constantine the Great and the rise of monasticism. The word "choir" is first used by members of the Latin Church. Isidore of Seville and Honorius of Autun write that the term is derived from the "corona", the circle of clergy or singers who surrounded the altar.
When first introduced, the choir was attached to the bema, the elevated platform in the center of the nave on which were placed seats for the higher clergy and a lectern for scripture readings. This arrangement can still be observed at the Basilica of St. Mary Major in Rome. Over time, the bema (or presbytery) and choir moved eastward to their current position. In some churches, such as Westminster Cathedral, the choir is arranged in the apse behind the altar.
The architectural details of the choir developed in response to its function as the place where the Divine Office was chanted by the monastic brotherhood or the chapter of canons. The chancel was regarded as the clergy's part of the church, and any choirboys from a choir school counted as part of the clergy for this purpoose. After the Reformation, when the number of clergy present even in large churches and cathedrals tended to reduce, and lay singing choirs became more frequent, there were often objections to placing them in the traditional choir stalls in the chancel. The pulpit and lectern are also usually found at the front of the choir, though both Catholic and Protestant churches have sometimes moved the pulpit to the nave for better audibility. The organ may be located here, or in a loft elsewhere in the church. Some cathedrals have a retro-choir behind the High Altar, opening eastward towards the chapels (chantries) in the eastern extremity.
After the Reformation Protestant churches generally moved the altar (now often called the communion table) forward, typically to the front of the chancel, and often used lay choirs who were placed in a gallery at the west end. The choir and rear of deep chancels became little used in churches surviving from the Middle Ages, and new churches very often omitted one. With the emphasis on sermons, and their audibility, some churches simply converted their chancels to seat part of the congregation. In 19th-century England one of the battles of the Cambridge Camden Society, the architectural wing of the Anglo-Catholics in the Church of England, was to restore the chancel, including the choir, as a necessary part of a church. By pushing the altar back to its medieval position and having the choir used by a lay choir, they were largely successful in this, although the harder end of the High Church objected to allowing a large group of laity into the chancel. Different approaches to worship in the 20th century again tended to push altars in larger churches forward, to be closer to the congregation, and the chancel again risks being a less used area of the church.