The family of Boyd continued to flourish until, in the fifteenth century, it was ennobled by James the Third, who owed to one of its members, Sir Alexander Boyd of Duncow, esteemed to be a mirror of chivalry, an inculcation into the military exercises, which were deemed, in those days, essential to the education of royalty. But the sunshine of kingly favour was not enjoyed by the Boyds without some alloy. Robert Boyd of Kilmarnock, who was raised to the peerage, under the title of Lord Boyd, and whose eldest son was created Earl of Arran, experienced various vicissitudes. He died in England, in exile; and his brother, Sir Alexander, perished in 1469, on a scaffold, erected on the Castle Hill of Edinburgh. The fortunes of the family were, however, restored in the person of Thomas, Earl of Arran, who married the eldest sister of King James the Third. The beautiful island of Arran was given as the dower of this lady: and her husband, who is said in the Paston Letters to have been a "light, clever, and well-spoken, fair archer; devoutest, most perfect, and truest to his lady, of Knights," enjoyed a short gleam of royal favour. His vicissitudes, however, befel him whilst on an embassy in Denmark, his enemies undermined him at home: he was driven to wander in foreign countries, and died at Antwerp, where a magnificent monument was erected to his memory, by Charles the Bold, Duke of Burgundy. His title was attainted, but his property was restored to his son; and in 1655, the title of Earl of Kilmarnock was added to that of Lord Boyd, which alone seems to have been retained by the family during the intervening generations.