Archaeological excavations have shown that the first castle on the site was a Norman motte and bailey, built sometime in the mid 11th century.

The head of the Umfraville family, Odinel II, refused to support him and as a result the Scottish army tried to take Prudhoe Castle.

The following year William attacked the castle again but found that Odinel had strengthened the garrison, and after a siege of just three days the Scottish army left.

Through his mother, Gilbert II inherited the title of Earl of Angus, with vast estates in Scotland, but he continued to spend some of his time at Prudhoe.

In 1316 King Edward granted Robert 700 marks to maintain a garrison of 40 men-at-arms and 80 light horsemen at Prudhoe.

In 1381 the last of the line, Gilbert III, died without issue and his widow married Henry Percy, 1st Earl of Northumberland.

That same year it was granted to the future Duke of Bedford, (a son of Henry IV) and stayed in his hands until his death in 1435, whereupon it reverted to the Crown.

However, Henry Percy, 3rd Earl of Northumberland fought on the Lancastrian side in the Wars of the Roses and was killed at the Battle of Towton in 1461.

Following forfeiture of the estates the castle was reported in August 1537 to have habitable houses and towers within its walls, although they were said to be somewhat decayed and in need of repairs estimated at £20.

Between 1808 and 1817, Hugh Percy, 2nd Duke of Northumberland carried out substantial repairs to the ancient fabric and replaced the old dwellings within the walls with a Georgian mansion adjoining the keep.

On the west side of the outer ward is the manor house, built in the early 19th century, and containing a visitor's shop and exhibition rooms.