The Church of St John Baptist, Cirencester, is by some distance the largest parish church in Gloucestershire, and one of the biggest in the whole country; 180 feet long and 104 feet wide, centred on a square tower 134 feet tall. Some parts date from the 12th century though the most is from the 15th and 16th centuries, utilising the perpendicular gothic style, and in common with many other medieval religious buildings, the church was originally part of a monastery (Augustinian), founded here by Henry I in 1117, on the site of an earlier Saxon church which itself replaced an ancient Roman settlement. Because of its size, grandeur and historical importance, the church is known, informally, as the Cathedral of the Cotswolds, and is constructed out of the local Cotswold stone, a yellowish limestone, now aged and weathered, that gives the building a rich, warm colour, especially when illuminated by the sun.
Besides the tall tower, the exterior is also notable for the south porch, originally a separate, administration building, connected to the church in the 18th century. The church interior includes five chapels and an assortment of historical artefacts including a 14th century font, a 15th century pulpit, fragments of wall paintings, coats of arms, a collection of tombs and memorials, often very ornate, and the Anne Boleyn cup, given by Anne to a local doctor (Richard Master) who treated her, and presented to the church in 1561. The church is a welcoming place, free to enter and regularly used for services; free guided tours are often provided. Parking is available right outside, along Market Place in the centre of Cirencester.
Cirencester was originally a Roman town (Corinum), settled early in the first century, and a church was constructed here around 300 AD. The Roman building was destroyed by the Saxons, who installed a replacement on the same site, and this was in use for over 400 years, until removed when Henry I founded the Abbey of St Mary, in 1117. A much bigger church was erected, together with other monastic buildings, and the place was modified on several occasions up until the Dissolution of the Monasteries in 1540, including rebuilding of the nave on two occasions, around 1250 and 1520. The lady chapel (also known as St Mary's chapel) was added around 1250, and a great hall just to the south of the church in 1490, subsequently used as the south porch. The large size of the abbey in relation to the relatively small population of the town was due to the success of the local wool trade; several local families were able to finance its construction. The abbey became a parish church following the Dissolution, though most of the other monastic buildings were swiftly demolished. As with nearby Tewkesbury Abbey, the church at Cirencester was extensively restored in late Victorian times under the guidance of Sir Gilbert Scott, and it has also been repaired more recently, including cleaning of the south porch.
The usual entrance to the church is via the central corridor of the south porch, then through a small side door which opens into the south aisle of the nave. The interior is rather dark and austere, due to a combination of subdued lighting, heavy wooden ceilings and aged, greyish masonry; the walls are mostly rough stone or old plaster, lacking any recent decoration, this in part to preserve a few fragments of ancient paintings. The greyness though is offset by an array of richly-coloured stained glass windows, mostly Victorian, some medieval, and the walls are adorned by many monuments, often very elaborate. The nave is flanked by two rows of tall, slender, fluted columns, and extends east to the choir and chancel, including the high altar, while the aisles contain five chapels. The small Garstang chapel is on the south side, enclosed by a carved wooden screen, while the large Trinity chapel (built in the mid 15th century) is to the north, containing a collection of funerary brasses. In the northeast corner is the lady chapel, the oldest, featuring a huge tomb of Humphrey Bridges (died 1598) and family, complete with coloured carvings and effigies. This chapel is separated from the chancel by the St Catherine's chapel, the most ornate, containing a fine altar with gilded reredos at the foot of a beautiful window, beneath an elaborate, fan-vaulted ceiling. Other notable tombs include those of George Monox (died 1638), a wealthy merchant, and Thomas Master (died 1680), a local MP.
The front of the church is dominated by the south porch, yellow-orange in colour following its recent cleaning. The building is rectangular in outline, three stories high, topped by decorative pinnacles, crenellated parapets, and carved bay windows. The stone of the church itself, not recently cleaned, is much darker; greyish yellow. The west end of the south aisle is notable for incorporation of what was originally a flying buttress, built around 1440 to support the tower, now forming part of the later addition. The west front is centred on a plain window above a simple double door, not usually open, and like the south side this adjoins a paved area, along Market Place. The north side of the church borders parkland, formerly the site of Abbey House, a country mansion demolished as recently as 1964, occupying part of the site of the old monastery. The east end of the church overlooks the graveyard.