[3] During the rout following the Jacobite defeat, the Earl of Kilmarnock was captured and taken prisoner, dishevelled and bareheaded, and was reportedly recognised by his son James, who placed his own hat on his father's head.

[4] This was the last time they were to meet, as Kilmarnock was then transported to London, tried for treason, and executed four months later; forfeiting all his lands and titles, which deprived his son of his inheritance.

Trying to cover some of his father's debts, which he had also inherited, James Boyd sold the ruined castle to the 13th Earl of Glencairn.

Along with the title Earl of Erroll, he also held the ceremonial hereditary office of Lord High Constable of Scotland.

Together, they were the parents of twelve children, including:[2] Lord Erroll died on 3 June 1778 at Callendar House, aged fifty-two, and was succeeded by his eldest son, George.