According to tradition, Richard de Redvers, Earl of Devon, first raised a castle here around 1106, but if so nothing remains of it. Hugh Courtenay built the present stronghold soon after 1300, and the quadrangular plan is very typical of that era but would be unlikely in a Norman castle.
We may compare Hugh's reconstruction of Okehampton Castle, where his work was conditioned by the old motte and bailey layout. Tiverton's quadrangle was surrounded by a curtain wall, which remains on three sides. There were towers at the corners but only the two southern ones remain. The southeast tower is circular and rather picturesque with its later conical roof; the larger southwest tower is square and ruinous.
Windows piercing the curtain between them, some retaining their tracery, show that important buildings stood here, the largest marking the site of the chapel. These windows and the relatively slight projection of the angle towers show that the castle, though a product of the Edwardian age, was not too serious a fortress. The gatehouse in the middle of the east front exemplifies this. Though undeniably strong, it eschews Edwardian defensive principles, being a simple tower with one floor over the vaulted gate passage. The part, which projects in front of the curtain, is a slightly later extension.
Hugh Courtenay became Earl of Devon and Tiverton was the favorite seat of subsequent earls until their attainder in 1539. On the Courtenays' reinstatement, the castle was not restored to them but passed instead to the Giffards. They abandoned the old residential buildings on the south and west and built an Elizabethan house in the northeast corner of the courtyard, backing onto the old curtain. This house still exists in a much-modified form. Afterwards, the west side of the castle was torn down but the rest was left intact out of courtesy to the occupants.