The tower which dates from around 1200 and the adjacent west wall are all that remains of the original church building.The dedication to St Michael is thought to derive from an early connection with South Malling where a Saxon monastery and College of St Michael were established and the church may have been founded by an early Archbishop of Canterbury. Some antiquarians believe that it was instituted as the church of the castle, and the use of the expression tanquam matrici ecclesie (mother church) in the 16th century does seem to imply that St Michael’s held a position of seniority in the town, or indeed more widely.
The arcade of octagonal piers separating the south aisle from the nave were built in the 14th century. By the time of the Reformation (16th century) St Michael’s was in a deplorable condition. Other churches within the walls of the town were lost but St Michael’s survived. The fortunes of St Michael’s suffered another serious setback during the Puritan revolution (1640-1660) and even after the Restoration (1660) the citizens of the town remained predominantly Dissenters so that the church continued to decline.