Scalloway Castle was built by Earl Patrick Stewart. Although the now unreadable inscription above the entrance door says 1600, the work in fact started in late 1599 – just a couple of years after Lawrence Bruce of Cultmalindie had his castle at Muness built - and continued for 5 years. The work at Scalloway Castle was directed by Andrew Crawford, the Earl's master of works, who also had built Muness Castle.
Scalloway Castle was built as a fortified stronghold, a demonstration of Earl Patrick's power and interests in Shetland in general and against the Lawrence Bruce, half-brother of Earl Robert Stewart and his father's former right-hand man in Shetland in particular.
The design of the castle is that of an L-shaped towerhouse with a rectangular main block (some 18m by 10m) with a massive square tower (8m by 8m) at the southwest angle. Both the main block and the tower, which is taken by the mainstairway and the landings, were built with three upper floors. Although the roof and the flooring of the two uppermost storeys are gone, the structure itself survives in reasonably good condition.
The doorway to the castle which opens to the ground floor of the tower is set strategically within the angle of the main block and the tower. It is covered by a gunport beside it. Most of the other fortifications like the shotholes which originally were below of all the windows disappeared due to various alterations. The same happened to the fortified outbuildings, too.
Despite the corbelled footing of the turrets at every corner of the tower, (a typical "handwriting" or "trademark" of the masterbuilder Andrew Crawford), the only decoration of the castle are three armorial panels and an inscription commemorating Earl Patrick above the doorway.
The inscription was recorded in 1800 as "Pium Vilicus , Mane of Orkney quod Shetland. James V Rex rgis of Scots. Ut domus cuius crepidoinis est in a silicis vadum sto sive in sand vadum cado." Translated from Latin into English this reads "Patrick Stewart, Earl of Orkney and Shetland. James V King of Scots. That house whose foundation is on a rock shall stand but if on sand shall fall."
The lack of other decorative elements, too, points to the fact that Scalloway Castle was first of all a stronghold and not so much a prestigous residence like the Earl's Palace in Kirkwall. Nevertheless, there is an account from 1703 that mentions some remains of colourful wallpaintings and decorations inside the castle.
The main block shows the typical structure of a towerhouse of that time. On the ground floor we find next to a storeroom a large kitchen with a big fireplace and a well (!) serving the whole castle. The first floor gave space for an impressive hall with nine quite big windows and two fireplaces. The second floor was divided into two apartments each fitted with its own garderobe or toilet; the third floor was divided into three smaller apartments, but all of them had their own window and fireplace like the two apartments on the second floor. More smaller apartments existed in the upper floors of the tower and the corner turrets.
After the execution of Earl Patrick, the castle declined in importance; in later years it housed some of Cromwell's troops for a short time and then fell into disrepair until it was taken in state guardianship in 1908. The castle is now in care of Historic Scotland. Open to the public, the key is available from the Scalloway Hotel.