the see was at Caistor, bishop Berhtred must have been the last occupant who resided there. Then came the invasions of the Norsemen and Christianity was, to a large extent, obliterated in this part of England.
The earliest part of the existing church is the lower stages of the tower, probably dating from the first half of the eleventh century. This has many puzzling features and it is impossible to be clear about the form of the church of which it was a part. There are blocked arches in the north and south walls, but the latter does not at all correspond internally and externally. It is obvious that numerous repairs and alterations have been carried out and possibly the stones marking the external arch are not in their original position. A similar explanation may apply to the west face of the tower, in which a low Norman doorway may have taken the place of a wider Saxon arch, traces of which can be seen to the south of this door. The internal measurements of the tower at ground level are 17½ feet x 15½ feet and the walls are almost 5 feet thick. These dimensions considerably exceed those of other pre-Conquest towers in north Lincolnshire and may indicate a comparatively later date. It is possible that the Saxon church was cruciform with a central tower.
Probably about 100 years after it was erected the limbs of this church were taken down and a long, narrow, Norman church was built, extending eastwards from the tower, of which the surviving traces are to be seen in the two slender cylindrical pillars at the entrance to the present sanctuary. These probably marked the division between the nave and the short, apsidal chancel. The Norman corbel table over the south wall of the chancel can be seen on the nineteenth century lithograph (plate Ia). At the same time the tower was carried up to its present height (without the parapet) and round-headed windows were inserted in the top stage. These can now only be seen from inside as they were covered in the fourteenth century by the large existing windows.
The next development, which may have taken place between the years 1240 and 1250, was a very important one. The nave walls were taken down and replaced by arcades of four bays, each with octagonal pillars on high square bases, north and south aisles were made, access to the latter being gained