The base of the tower dates from the 11th century. The doorway is Tudor. The large window is in perpendicular style and the two windows above this are 15th century. The parapet walls and pinnacles which top the tower were built in the 17th century. Inside the church are the Swearing Font, and the Seafarers Window. The Swearing Font: in 1718 the local churchwardens were so appalled by the drunken swearing of a parishioner that they fined him £5. With the money they commissioned a new font, and had carved on it the words 'Good people all I pray take care that in ye Church you doe not sware As this man did'. An entry in the registers for 30th August 1718 explains: "Elizabeth daughter of Robert and Eliza Wood, being ye first child which was baptised in the new font which was bought out of five pounds paid by John Norman who some months before came drunk into ye Church and cursed and talked aloud in the time of Divine Service, to prevent his being prosecuted for which he paid by agreement the above said five pounds. Note that the wise Rhyms on the font were put there by sole order of Robert Joyce then Church Warden". The Seafarers Window: a 15th century window with modern glass commemorating the close association between Tollesbury and the sea. The centre light shows a post resurrection appearance of Christ. In the left hand light are images of four yachts that have contended for the 'The Americas Cup'. Tollesbury yachtsmen have been intimately connected with the yacht race since it started in 1851, participating in fifteen of first sixteen races, and Captain Ted Heard of Tollesbury skippered three of the entries. In the right hand light are four Essex coastal vessels; a Billy Boy; a ketch rigged barge; a 'Stackie' (built to carry straw and hay to London); and a Tollesbury oyster smack.