The body of the church was built in 1715 by John James to effectively act as a private chapel for nearby Cannons owned by the Earl of Chandos. The 15th century tower was retained from the old parish church. The ceiling was painted by Laguerre and the walls by Sleter. The east and west end ceilings are by Bellucci. On the north side is the anteroom and main Chandos Mausoleum built 1735-36 by James Gibbs and housing the huge Grinling Gibbons monument to the Duke of Chandos and his wives.The walls and ceiling are decorated by Sleter and G. Brunetti. The whole building is an overwhelming baroque experience.