Castle of St John is a fortified tower house located in the centre of Stranraer, in Dumfries and Galloway.
Tower-houses are the domestic versions of medieval castle towers, these were built and used by Scottish lairds throughout the sixteenth and seventeenth centuries.
The tower house was built in 1510 by Adairs of Kilhilt, who emigrated from Ireland. They originally settled in the Portpatrick area and they may have built the original castle at Dunskey. Over time the Adairs extended their land-holding south to Drummore and north to Inch. By 1484 they had acquired the lands in Stranraer and built a chapel dedicated to St John. This area of land became known as St John’s Croft or Chapel.
The castle was originally was called the Place of St John or the Castle of Chapel. By the late 1500s a small settlement, also called Chapel, had grown up around the tower-house. The Adairs used the castle as a family home and a centre for the administration of the estate, collecting rents and entertaining guests. The main hall is thought to have served as the laird’s court. In 1595, Ninian Adair created a Burgh of Barony at Stranraer. This turned the town into a self governing community with trading privileges and provided Ninian Adair with income from property rents and other tolls collected within the new burgh. In 1608 the castle passed by marriage to the Kennedys, from Ayrshire, and by the 1670s it was in the possession of the Dalrymples of Stair.
In the late 1670s, the Castle of St John was used as a military garrison. Government troops had been brought to Wigtownshire to suppress the Covenanters, a religious dissent group who threatened the political establishment. The Covenanters were extreme Presbyterians who refused to accept the authority of state-imposed bishops. The Covenanting movement was particularly strong in Galloway and outbreaks of violence were common.
In 1678, John Graham of Claverhouse was appointed as the local military commander, tradition has it that he used the Castle of St John as his base for it was the largest building in the town, as well as being defendable. The outbuildings were used for stabling and accommodation for his troops. As the castle belonged to Covenanting sympathiser, John Dalrymple of Stair, it sent a clear message
By the early 1800s the building was empty so in 1820, the Commissioners of Supply, who were basically early county councils, approved plans for converting the building into a ‘secure and salutary jail comprehending two cells for criminals, three rooms for debtors and a Courtroom’. The conversion cost was £785. One of the biggest changes was the demolition of the original gabled roof and its replacement with a flat roof doubling as an open exercise yard for the prisoners. In 1854, a new prison was built in Lewis Street but demand was such the cells at the castle continued in occasional use until 1907.
During the Second World War, the town house was used as fire watching station and ARP base.
The Castle was restored in 2010 by Dumfries and Galloway Council, with assistance from the Heritage Lottery Fund, Historic Scotland and Landfill Communities Fund.