The story of Decuman begins in the 6th Century. From a monastery in Pembrokeshire, along with his cow, Decuman sailed across the channel in a curragh to settle in West Somerset. His name is possibly of latin root meaning a smallholder who paid a tithe which may indicate that he or his family lived at the end of the Roman administration. It is likely that he lived at or close to the site of the present day church building.
St Decumans is situated high above the town of Watchet and for many years was the parish church of both Watchet and Williton. The oldest part of the building dates back to the 12th century with additions in the 13th century and further substantial additions in the 15th century. It is believed that the church on this site replaced a former chapel that was nearer the sea, near Dawes Castle. Little is known of this chapel. Records at Wells Cathedral show that the church was given to them by the Brito family (although it is on land belonging to the FitzUrse family) in 1190 - the Brito and FitzUrse families were disgraced when Simon Brito and Reginald FitzUrse were involved in the murder of Thomas Beckett in Canterbury in 1170). The church contains numerous memorials to the Wyndham family who have been associated with the parish for many years. These include a carved wooden box pew dated 1699 and a depiction of Henry Wyndham (died 1613) and George Wyndham (died 1624). These are in the Wyndham Chapel at the north east corner of the church. The "wagon" roofs above the nave and side aisles are considered to be of some note. The church also contains a fine rood screen, a highly regarded altar rail and between the choir stalls is a floor of 13th century tiles which are thought to have come from Cleeve Abbey. There are also some rich carvings with figures of angels. These date from the 13th century.
The Holy Well is to be found a short distance down the lane beside the church. It is believed to have been a known Holy site since the 5th century and probably predates Decuman himself.
The chapel is a place of prayer, meeting and worship in the very heart of Watchet. Nothing remains of an earlier 14th century chapel in Market Street which was established so that a chantry chaplain could say prayers for the disgraced FitsUrse family. During the reformation, chantry chaplains were abolished and the chapel was sold in 1548. In 1549 another chapel was established in Market Street and lasted until around 1830 when it became a ruin. The present chapel was established by the Wyndham family as a "mission to seamen" in 1907 and continues as a place of regular worship to the present time.
St. Decuman's, Watchet