The church is reputed to have been founded by Saint Aldhelm in the 7th century.[3] It is thought that this earlier building was destroyed by King Canute in 1015.[3] The present building dates from about AD 1030. Anglo-Saxon features include a tall, narrow nave and chancel, late Anglo-Saxon wall-arcading in the north west aisle and traces of a Saxon door.[4] The building has been altered and expanded over the years but the nave and a tiny window in the north side of the chancel are original features. On the north wall of the chancel are 12th-century frescoes depicting Saint Martin on horseback, escorted by attendants, dividing his cloak and giving one half to a naked beggar.
On one of the walls a number of red stars have been painted, possibly representing plague deaths in the 17th century.[2]
During the Great Fire of Wareham in 1762, the church was used as a temporary refuge for those who had lost their homes. Later the church fell into disuse but at the beginning of the 20th century a programme of restoration began and the church was rededicated on 23 November 1936.