[1] Excavations carried out in the 1960s[2] discovered that the foundations and the surviving nave walls were late Saxon, predating the Norman conquest by a few years.

[1] A century later, the building took its present form when the chancel and central tower were built, creating the simple three-cell (nave–tower–chancel) layout.

[2] At St Julian's Church, the cell walls themselves were removed by the 14th century, but the window (a form of hagioscope) and a door remain in perfect condition,[2] and the roofline can still be seen.

[1][3][5] Restoration in the 19th century renewed some of the windows—for which the Perpendicular style was retained except in the east wall, which was given a large lancet window—improved the north aisle and added a buttress to the outside of the nave.

[1][3][5] St Julian's Church is a flint building with stone dressings, and consists of a nave with a north aisle, chancel and central (but partly offset) tower.

[5] Interior features include the Lewknor family's tomb in the Easter Sepulchre, a pulpit with two decks, an organ in its own gallery, a 14th-century chancel screen, a rare singing-desk and some box pews.

[1][2][3][5][6][7] The Lewknor tomb has ogee mouldings and a series of carvings depicting the Pietà, the Resurrection of Jesus and the Trinity.

[10] The organ was moved from its original home in Brighton Aquarium, and still bears a bronze plaque stating its former location.