Most of the surviving building work dates from the 12th century, although the site of Prudhoe Castle has strong Norman origins. As a great fortress, a baronial home, and a powerful administrative centre, Prudhoe Castle has played many active roles throughout its history. Situated in the Tyne valley in Northumberland, it was inevitably involved in the border wars between Scotland and England, and was subjected to siege at various times.
The plan of Prudhoe Castle is roughly in the shape of a figure of eight, the inner and outer baileys now separated by a Georgian manor house that was built on the site of earlier residential buildings. Within the inner bailey, the most substantial building is the great tower. Originally two storeys high, the tower was extended in the 14th/15th century to provide a further level with turrets. Only the south west turret still exists, and the original height of the tower can be seen by its roof line running along the inside of the west wall.
Adjacent to the great tower lie a range of 13th century buildings known as the 'forebuilding', and the eastern wall of this structure was later consolidated into the building of the 19th century manor house. Towards the west of the inner bailey are two rounded towers, also dating from the 13th century. The tower in the north west corner of the bailey is virtually intact, whereas only the base remains of the south west tower.
Of several early buildings contained in the outer ward, the great hall was the most impressive and important. Little more than the foundations, hugging the north curtain wall, are visible today but indications of its former grandeur have been found. East of the great hall, a series of domestic service buildings were situated, including a 16th century brewhouse. To the south are the fragmentary remains of a medieval building, possibly once used as lodgings. A remarkable survival is the 12th century gatehouse, a relatively simple structure with a gate passage running beneath a series of arches. During the 13th century a chapel was built over the gatehouse, and the narrow lancet windows can be noted from the passage approach. A further extension to the gatehouse, built above the chapel, was added in the 14th century, and later still a barbican was constructed.
Although continuing to be inhabited during the 17th century, Prudhoe Castle had become largely ruinous by that time, and some 100 years later it started to collapse. At the beginning of the 19th century, the 2nd Duke of Northumberland carried out essential repairs to the tower and walls, but most of the ruins were cleared at this time. Further repair work was effected in 1912. Prudhoe Castle came into the possession of the notorious Percy family in 1398 and, despite several periods of forfeiture over a 200 year period, it is still owned today by the Duke of Northumberland, a direct descendant of the mighty Northumberland baron, Sir Henry Percy.