In the early 14th century, the majority of the walls and towers were built primarily from local red sandstone, which is found abundantly in the area.

After the rule of Norway, the castle continued to be used by the Church due to the cathedral built there – the see of the diocese of Sodor and Man – but was eventually abandoned in the 18th century.

The most spectacular finds were the 10th century grave of "The Pagan Lady" which included a fine example of a Norwegian necklace and a cache of silver coins dating from about 1030.

Peel Castle features today on the reverse side of the £10 banknotes issued by the Isle of Man Government.

Robert Anderson examined the ruins to determine what repairs were required to restore the cathedral, and he reported to the island's Lieutenant Governor in 1877.