Called Kilmarnock Castle until 1700, Dean Castle was home to the Boyds, followers of the Hereditary Steward in his campaigns to win territory in the west for the Kingdom of the Scots. Robert Boyd took part in the victory over the Norse at Largs in 1263 and was rewarded with estates in Ayrshire. During the Wars for Scottish Independence, Robert's son was murdered in the massacre of Scottish lords and knights carried out at Ayr in 1296 on the orders of Edward of England. The grandson of the line. Sir Robert Boyd, dedicated himself to revenge, serving with Wallace at the subsequent Burning of the Barns in Ayr and acting as the Guardian's second-in-command. When Wallace was executed in 1305, Sir Robert put his sword at the disposal of me Bruce, riding with him through the difficult years after the defeat at Methven in 1306. In recognition of his military skill, Boyd was given command of the right wing of the Scots army at Bannockburn in 1314. Boyd's division successfully withstood the charge of the English cavalry that day and in reward, he received the lands of Kilmarnock and West Kilbride in 1316.
Much of the surviving construction at Dean Castle dates from the mid fifteenth century when the Boyds were raised to the peerage by James II in 1454. Known for his honesty. Lord Boyd was made Regent of Scotland for the infant James III in 1460. The family's new social status was acknowledged in the architecture at Dean; the comfortable apartments known as the Place or palace were raised between 1455 and 1468. Unfortunately, Regent Boyd had little opportunity to enjoy his palace as the jealously of other noble houses led to his downfall and flight into exile in 1469. Surviving this setback however, the Boyds recovered their lands at Dean and were granted royal permission to found the nearby burgh of Kilmarnock in 1592.
Later Boyds were loyal adherents to the Stewart cause. Charles II expressed his gratitude for this by making William Boyd the 1st Earl of Kilmarnock. Later members of the family suffered for their loyalty to the Scottish royal family. The 4th Earl served with Prince Charles Edward Stewart in 1745 and was captured after Culloden in 1746. His lands and titles forfeit, the Earl was taken to London and beheaded alongside Lord Balmerino. This fulfilled a horrific vision at Dean Castle some years earlier when the Earl's servants saw his severed head rolling around the castle floor. Damaged by fire, the castle passed through several owners including Lord Glencairn, the friend of Robert Burns. It now houses a fine collection of arms and musical instruments.
To Tour Ayr and Kilmarnock