by a door-way with nail-head ornament. A new wide chancel arch was made and a south aisle was added to the chancel. The windows of this building were probably tall, narrow lancets such as were reproduced in the nineteenth century chancel. The steep-pitched roof reached to a point just below the present tower windows and there was an opening in the east wall of the tower commanding a view of the whole interior of the building.
Some indication of the date when these enlargements and attachments were made is given by the unusual corbels over the north arcade, which are practically identical with several in the stone screen-work of the choir aisles in Lincoln Cathedral. The screen-work was erected during the episcopate of Robert Grossetete (1235-1253) and it is reasonable to suppose that masons employed at the Cathedral also worked at Caistor, where the church was in the hands of the Dean and Chapter of Lincoln. Somewhat similar corbels occur at Bracebridge and in the prebendal church of South Carlton. It is interesting to note that, when repair work was in progress at Caistor in 1862, a coin of Louis IX of France, who came to the throne in 1236, was found beneath the floor.
Bishop Oliver Sutton visited Caistor on June 29th, which would be the patronal festival, in the year 1291 but whether he did so with the intention of consecrating an altar or any other addition to the church is unknown.
There do not seem to be any architectural features remaining which belong to that period.
On April 3rd, 1311, Roger de Mortival, prebendary of Caistor, who later became Bishop of Salisbury, received licence to dedicate an altar in his prebendal church and it is possible that the Hundon chapel at the east end of the north aisle was built at this time.
In the middle of the fourteenth century new windows were inserted in the tower and aisles. (The latter were replaced in the nineteenth century). A new doorway on the north side was also provided. The trefoil headed three-light windows, with quatrefoils in the tracery and the ball-flower ornament of the door are characteristic of English architecture of the Decorated period.
The Guild of the Purification of the B.V Mary was founded