The original nave would have been as wide as the pillars in the photograph and somewhat shorter and lower than at present. The Guild of the Holy Cross, a mediaeval trade guild with religious and charitable aims, was formed in 1269 and between 1280 and 1330 gave the money to build the tower and rebuild the nave with side-aisles.
The roof was raised and the clerestory added by the College (see chancel). Henry VIII suppressed the Guild and closed the College and gave their assets to the town. The reformation era saw the destruction of the chantry, rood screen, much of the carving and most of the glass. The responsibility for the upkeep of the nave fell to the townsfolk.