Built in the C12 as a hospice for the priory, it became a parish church in the C13. The north side is C14 and the south aisle mid-C16. The tower is early C18 and the chancel C19. It contains the C12 tombstone of Gundrada de Warenne, joint-foundress of the priory.
A hospice west of the gate of Lewes priory provided hospitality for travellers and the poor. Of the gate, little more than one wall, with the C13 multi-shafted jamb of an arch, remains. The hospice became a church for the surrounding area during the C13 and survived the Dissolution in 1539, as by then there was a considerable population. Possibly an expanded hospital of St James nearby took over the functions of the hospice; this was founded by 1138 and is remarkably close to the priory.
The hospice was built in the C12 in two parts of unequal width, divided by an arcade; it is probable that one side was for men, the other for women. It is low and dark, as there was no clerestory. The arcade has heavy cylindrical piers and round-headed arches. The latter are quite plain and are obscured by paint and plaster, so that it is impossible to establish whether they are original or were altered later. In view of the originally utilitarian nature of the building it is conceivable that they are C12, but they are perhaps more likely to date from the conversion work of the C16. The piers of the first three of the five bays from the west are certainly original, though possibly altered, and the west respond is a complete pier, showing there was at least one further bay.
The north side was remodelled in the C14, but little but the square-headed westernmost window remains; this is largely renewed but retains some old stones in the head. Adelaide Tracy shows all but one of the others were then similar. Sir Stephen Glynne noted a ruined chancel with a window he dated to the C14. This is not on Horsfield’s engraving, but an engraving in GM and the Sharpe Collection drawing, though neither is wholly clear, show a three-light east window that looks post-Reformation. C15 alterations include the nave roof with tiebeams and crownposts and the fourth arch of the arcade, which has a four-centred head, two hollow-chamfered orders and triple shafts on the responds. It is said to have stood originally across the aisle at its eastern end and in its present position had a predecessor, for the west respond is a complete C12 pier.
The arch may have been moved when the gabled south aisle was remodelled in the C16. The presence of re-used moulded stones, especially in the west wall, suggests this dates from after the Dissolution. Built of flint and stone chequerwork, it has three- and four-light four-centred windows and a moulded west doorway in a square frame; a square-headed two-light east window is reset in the C19 vestry.
The nave was probably truncated because a west tower was also built after the Dissolution, assuming there had not been one earlier. A moulded doorway leading from the tower into the nave looks C14, but may have been moved, and the irregular angle-buttresses may also be earlier. This tower is known to have collapsed in 1698. Its replacement, with battlements, is dated 1714 and its reset west window resembles those of the aisle. It is built of brick except the buttresses which are of ashlar, probably re-used and the mason W Stephen was responsible. On the undated Sharpe Collection drawing is a pyramid roof in place of the small turret with a cupola, shown by Nibbs in 1852 and still present today. The date of 1714 is misleading, for at the bishop’s visitation of 1724 only the first stage had been built for lack of money. A join in the brickwork at the level of the bell-openings probably marks the break in construction, which was not completed until 1738. The final cost was £481 15s 4d. The related engraving in The Gentleman’s Magazine confirms that there was then no chancel, though it is not known if there ever had been one.
In 1845 a local carpenter, T Goldsmith, installed new seats. His plan also confirms there was no chancel and just a half-bay east of the arcade. In 1845-47 the railway to Brighton was built across the site of the priory and the ensuing protests contributed to the foundation of the Sussex Archaeological Society; among the finds were lead caskets thought to contain the bones of William and Gundrada de Warenne, the founders of the priory. The marble tombstone traditionally associated with Gundrada had been brought here from Isfield in 1775, so a neo-Norman chapel was built off the aisle. The exterior is quite plain, but the ornate interior has almost every form of Romanesque ornament, with a rib-vault and wall-arcading; the carving is said to be based on fragments found on and near the site of the priory. The architect was J L Parsons, a founder member of the Society, possibly advised by B Ferrey, though his obituaries do not list it, perhaps because by 1880 such work would have been seen as an embarrassment. At the same time, the north wall of the church was refaced in flint, though with unchanged windows, and a C16-style north doorway was inserted in the tower. Previously, as the Sharpe drawing shows, the main entrance had been on the north side, though no detail is visible.
A further restoration in 1883-84 by R H Carpenter and B Ingelow cost £2353. The work probably included the present C14-style north nave windows and the roof of the south aisle. The chancel was added, matching the flint and stone chequerwork of the aisle, with a five-light east window. A complete arch in C15 style replaced the eastern half-arch of the arcade. A timber and tiled extension with a steeply pitched roof, known as the Chapter House and standing to the south of the tower was added in 2009 by Mackellar Schwerdt Architects. More recently, the C19 pews in the church have been removed and replaced by chairs.
Hospitium, now church. Late C11 or early C12, C14, 1714-38, 1847, 1885. Flint walling on nave to north with stone dressings and buttresses, chequer stone and flint to south, as is north side of chancel. Red and blue brick chequer to lower stage of tower with red brick above and chequer battlements. Rubble stone diagonal buttresses with dressed stone dressings.
Plain tiled roofs. Octagonal cupola to tower with dome, finial and shark weathervane. Nave of five bays to north with four bay aisle to south. North windows C14, much renewed in 1885; south aisle windows C15, also renewed.
Interior: Tower arch, probably C14. South aisle arcade of four piers. late Cll or early C12. Drum-piers with unmoulded arches, probably renewed. Crown-post collar-purlin nave roof of C15 with downward braces from crown-posts to tie-beams. Also ashlar-pieces and braces from rafters to collars. Chancel of two bays, that to west C15, much rebuilt, that to east 1885, an identical copy. Curvilinear east window with C20 stained glass. Two-bay wagon roof with cranked principals. Chapel of William de Warenne and Gundrada, his wife, at east end of south aisle. 1845 by J.L. Parsons of Lewes in Neo-Norman style, advised by Benjamin Ferrey. Groin-vaulted with giant order in corners of chapel. Interlaced side wall arcading with dog- tooth string-course over. Round-arched windows with chevron ornament and order of columns with decorated capitals. Pair of similar wall openings to south with the two lead cists of William and Gundrada. Central slab to Gundrada, possibly of Tourmi marble with palmettes either side of a middle staff. Stained glass: north windows by Kempe, 1882-91.
Organ: 1904 with stone substructure in early Perpendicular style.