Parish church. Mid C14 origins, early C15 tower, altered late C15. Restored, chancel and S porch rebuilt 1849. Refitted and roof restored 1906-8. Flint rubble, cement rendered. Stone and red brick dressings. Yellow stock brick chancel. Lead nave roof. Slate chancel roof. Unaisled 4 bay nave with S porch, shorter, lower and narrower chancel, W tower. Nave to S has C14 2 centred entrance arch, triple moulded with shafted jambs, a foliate carved capital to right. Similar outer arch to C19 porch, coped gable parapet with kneelers. Nave has stone plinth, 2 restored late C15 windows of 2 cinquefoiled lights with traceried 4 centred arched heads, hood moulds. Short 2 stage angle buttresses to W, 1 buttress to E. Traces of sundial on quoin to E end of nave which has a coped parapet to a shallow pitched roof replacing an earlier steeper roof the line of which appears on the E wall of the tower. Nave to N: a large restored late C15 window, 3 cinquefoiled lights, 4 centred arched head. Blocked C14 entrance, pointed arch, double chamfered with moulded caps to jambs. Taller 2 stage buttresses, angled to W. Unbuttressed 3 stage W tower is slightly narrower than nave, square on plan. Moulded plinth. Stone quoins, brick in belfry. Lower W window, C15 restored, 2 lights with trefoiled heads with an upper hexafoil in a pointed arch. String courses to upper stages. Slit opening in second stage to S. 4 louvred lancets in belfry. Embattled parapet. Chancel: C14 plinth survives to S with opening for door to W of present door. S elevation has an entrance with flanking 2 light arched windows all in rendered surrounds, dentilled brick eaves. E end: large 4 light window in a broad pointed arch, angle buttresses, kneelers to shallow coped parapet. 2 similar 2 light windows to N. Interior: C15 chancel arch, 2 centred with wave and casement mouldings, continuous on jambs with respond caps. Tower arch is earlier C15, pointed, triple chamfered, chamfered respond piers with caps and bases. Nave roof retains C15 moulded wall plates, tie beams, purlins, ridge plate and principals, arched braces with pierced trefoils in spandrels. Carved figure corbels, grotesques, angels and figures in C15 dress. Nave S wall has rood stairs. Nave E wall to N of chancel arch has a C15 niche for a statue, 4 centred arched head, cusped with floriate stops, moulded square headed outer surround, frieze above with foiled and cusped panels. C14 piscina reset in chancel S wall at E end, cusped head to a moulded pointed arch. C15 font in tower arch, octagonal base with vertical roll mouldings at angles, larger octagonal bowl with outer Tudor flower and central quatrefoil friezes, cap and base, C17 cover. Early C18 communion rails, diagonally set slim vase balusters, moulded handrail, C17 communion table with turned legs. Royal Arms of George III over S entrance. Credo, Lord's Prayer and Ten Commandments panels removed to tower. Monument on nave S wall to Sir A. Meetkerke, Flemish ambassador to Queen Elizabeth I, d.1591, removed from St. Botolph's, Aldersgate in 1754; marble epitaph, moulded frame with arms. Early C19 monument to Meetkerke Family by J. Bacon. (Rev. J. Mearns, Transactions of the East Hertfordshire Archaeological Society, vol. IV, part 1, 1908-9: RCHM 1910: VCH 1912: Pevsner 1977).