The eastern arch, as we have observed, is Early English, and not unlikely to be the work of Bishop Simon, or his immediate successor. But the manner in which the south aisle is stopped by the turret, leads me to doubt whether the tower, in its present form, be not altogether an insertion into the original design of Bishop Simon's cathedral, and planned and executed about a century later.
Beneath the chancel is a fine crypt; its vault is not supported in the usual manner by insulated pillars, but by arched ribs, springing from short pilasters in the wall; of these there are thirteen, at small intervals, of one chamfered order. The vault is a pointed barrel one. The entrance into this crypt is by a passage of steps within the thickness of the south wall of the chancel. The present doorway has a plain square jamb, and seems to have been square-headed.
We have in England two striking examples of the combination of miltary and ecclesiastical structures, Porchester, and Dover, in both which cases the church within the walls is much more than a mere garrison chapel, as was probably that in the White Tower, in London; nor was the fortress a mere defence to the church or monastery. Peel castle and cathedral offer a similar instance. That the little Isle of St. Patrick was devoted to purely ecclesiastical purposes, at the time of the first introduction of Christianity into the Isle of Man, is not impossible; but its position was too important to allow it to remain long unoccupied as a military station. The very name it bears, supposed to have been given by the Scots after their conquest of the territory, implies that it was then a fortification. On more than one occasion it was used as a state prison; and the crypt under the chancel is pointed out as the dungeon in which Eleanor, the wife of Humphrey, duke of Gloucester, was imprisoned.
The tower and other parts of the castle about the entrance, which is south of the cathedral, seem to belong to the early part of the fourteenth century; the masonry is strong and careful, though not very regular, and the blocks of stone larger than those used in other parts of the building. (See engravings on opposite page.) From the difficulty of access, this part must have been very defensible before the general use of artillery. The rest of the wall is of a much later date.
