It is a 19th-century Anglican re-foundation of a medieval chapel, traditionally said to have been created by one of the assassins of Thomas Becket.
The church is dedicated to St Thomas Becket, Archbishop of Canterbury, who was murdered in 1170 by a group of four English knights acting – so they mistakenly believed – on the orders of Henry II.
Since Becket had defended the privileges of the Church against Henry, he was regarded as a martyr and canonized in 1173.
The four murderers were instructed, in order to atone for their sins, to serve a period as confreres (associate brothers) of the Knights Templar, but it is believed that one of them, Hugh de Morville, also elected to found a chapel dedicated to the saint as a private penance.
It was this chapel which would eventually become the Church of St Thomas the Martyr.
The precise foundation date is uncertain, but probably in the 1170s, and certainly by the early 13th century.