Passing into the nave, they are at once impressed by the size of the church and the height of the oaken roof. Two long vistas, one looking towards the altar from the West end and the other seen from the altar steps with the wide chancel arch framing the tall narrow one leading to the tower, will reveal to them the noble proportions of the nave and its arches.


There was almost certainly a stone church on the site in late Saxon times, although there is no mention of one in Doomsday Book. Some people think the triangular-headed arch in the North aisle was the doorway of this building; the remains of a zigzag dripstone between the arches of the North aisle imply that this was the outside wall of the Norman church built by Gilbert Bassett about 1120. The great central arches that once supported a tower also belong to this period.


By the 13th century the church had been given to Bicester Priory which stood roughly where Old Place Yard is now. The priory supplied the vicars and at intervals of about a century enlarged and improved the church. The chancel was extended in the Early English period (13th century) and the priest’s door made in its South wall; four arches were cut in the South wall of the nave and the South aisle was added; the fine arch between this aisle and the Lady Chapel was built then. So was the South doorway. In the Decorated period (14th century) the North chapel and the North aisle were built, three arches being cut in the North wall of the nave. The North chapel is now used as the choir vestry; a wooden screen leading from this to the priest’s vestry is painted with a design of flowers, birds and insects; dated 1882, it is a good example of its period. The Perpendicular Period (15th century) was the one that gave the building its present appearance. The central tower was taken down, its West arch removed and the crossing thrown into the nave. The nave was heightened, the clerestory added and the nave roofed with timber supported on twelve fine stone corbels, carved heads of beasts and grotesques. The West tower was built with a splendid perpendicular arch opening into the nave. Parapets were added to the outside walls and the porch was built.