The plan of a mediæval castle was, generally speaking, as follows: There was an outer wall surrounded by a ditch, over which a drawbridge would give access to the main entrance. Then separated from the first by a second ditch would be the second (the inner) wall. Both walls would be strengthened by towers at suitable points. Within this inner ward, as the space inside the inner wall was termed, the chief living rooms—the barracks, so to speak—would stand. Finally, there would be the donjon or keep, the strongest of the castle buildings, frequently erected on a mound, and capable itself of withstanding for some time a hostile attack even though the rest of the castle was in the enemy’s hands.

Tattershall Castle was defended by an incomplete outer moat, which, starting from the north-east angle of the area, went along the north and west sides, and communicated with the river Bain; there is still some water in portions of this ditch. It probably was carried eastwards so as to enclose the church, but there is a noticeable dip in the ground on the eastern side of the castle area, which is probably the same moat defending that portion of the castle. From a plate of the castle published by Buck in 1727 (which is in the writer’s possession), much knowledge can be gathered of the arrangements and buildings of Tattershall at that date. The inner moat was complete, and the outer wall which surrounded it, for the most part of brick, is in fair condition; it was supplied with water from the outer moat by a culvert piercing the outer bank and wall about the middle of the north side, which is plainly visible, and around which the bank is faced with stone. This, according to Buck, was protected by a strong and tall tower over it. On the east side of the moat may be seen a blocked up arch, which was connected with the outer moat at that point, and ran eastwards beneath the church to that part of the moat. The main entrance to the castle was evidently a little north of this arch, much in the line of the present pathway, for Buck plants a large gateway with two towers and portcullis here, on the inner side of the inner moat. Just outside and to the eastwards is a brick building of two storeys, and of exactly similar work to that of the rest of the castle. This house, which was probably used for guard-rooms, had at the north-west angle a turret staircase, and the only door on the ground floor was originally on the southern end, opening on to a terrace wall which defended this part of the castle. The outer wall was about twelve feet high (judging from the mark where it joined the house), with arched recesses and loopholes, and over all a platform with a crenellated parapet. A brick turret was at the south end of it, and the ruins of this and the drain into the moat are still visible. On the south side of the inner moat can be seen some stone corbels in the brick-facing wall, which were evidently to support a drawbridge. On the west side of the outer wall is a large brick one-storeyed building (with little arched cupboards or recesses in the walls, as will be found elsewhere), probably a guard-room, and the ruins of a strong tower farther to the north and east, on the edge of the outer moat.

On the south of the inner court is a large piece of ground, elevated and surrounded by a stone wall, except on its eastern side; this was probably an adjunct of the original castle, and was used for tilting and other exercises. It was approached doubtless by the drawbridge already mentioned. Eastward it joins a still larger portion of ground on the south of the church—the castle garden or pleasaunce. This is walled in partially with brick, and has had two doorways in the south side. In the spandrils of one were the coats of arms of Cromwell and Tattershall quarterly, and that of Deincourt.

The inner ward now is nearly flat, and contains no buildings save the great tower or keep, having unfortunately been levelled about 1790. Besides the entrance-gate already mentioned, we find from Buck’s view that in 1727 there still existed the eastern portion of the chapel, showing an apse of which two perpendicular windows were visible, and a great part of the dining-hall, which had a fine bay window and five other windows. To the left of the keep, and in the left foreground, are some buildings which very possibly were the remains of the castle of King Henry III.’s date.

Next we come to the chief feature of the place, the so-called Castle, which in reality was only the representative of the keep of earlier days. The inner ward wall joined it at the north-east and south-east towers, where the marks are plainly visible; the north, west and south sides were defended by the outer moat. It is 87 feet long by 69 feet wide, and the parapet of its angle turrets is no less than 112 feet above the level of the ground at its base. It is almost entirely constructed of small red bricks, traditionally supposed to have been brought from Flanders, though there is no reason why they should not have been made in the county. The walls externally have patterns, chequers, and lozenges in blue-black bricks upon their surface, and the groining of brick in the upper rooms is most delicately moulded, and may well serve as a lesson to us, even in this twentieth century, in artistic workmanship. On this work still exists considerable traces of pink plaster with red lines, to imitate brickwork—a curious case of carrying coals to Newcastle! Local stone (Ancaster probably) is used for the windows (which retain most of their tracery and mullions, except those of the ground floor), the machicolations, the battlements (in one place cement has been used for repairs), and the very admirably executed chimney-pieces, which will receive special attention later on. There are brick relieving arches over all the windows, doorways, and fireplaces in the castle. The large windows, which are more evident on the west, the exposed side, than on that facing the inner ward, show that the great change in warfare was in progress—that “villainous saltpetre” was altering the type of fortification from a massive tall keep like Rochester or Conisboro’, or the Edwardian castles of Harlech or Conway, to low-walled earthworks, such as those which still surround Berwick, and which were erected in the “spacious times of great Elizabeth”; also, these windows show that the nobleman’s castle was changing into the nobleman’s palace or mansion, of which, again, the Elizabethan buildings, such as Longleat, Hatfield, and Haddon Hall, are the finest examples.

Tattershall Castle, from the South-West.

The basement storey contains a large central room, with a very flat arched ceiling, a room in each of the towers, except the south-eastern one (which contains the staircase), and a room in the thickness of the eastern wall, which has similar arched recesses in its north and south walls to those already described. There has been a well in the centre of this basement area. A staircase leads down to the central room from the outside of the east wall.

There seem to have been no less than forty-eight separate apartments, four of these being very large (about 38 feet long by 22 feet wide and 17 feet high), and occupying the centre of the building one over another.