His family supported Mary, Queen of Scots, even after her imprisonment at Lochleven Castle, her abdication in favour of her one-year-old son on 24 July 1567, her defeat at Langside in 1568 and her flight to England shortly afterwards. In 1570 Moray, who was regent during part of the minority of King VI, was assassinated by John Hamilton of Bothwellhaugh, a supporter of Queen Mary, at Linlithgow. John's father (the Duke of Châtellerault and 2nd Earl of Arran) had been imprisoned by Murray at the time and John himself might have had a hand in the murder. His successor, Regent Lennox, died in 1571 from a shot in his back during a skirmish at Stirling with the Queen's party. Finally, on 23 February 1573, his father gave up his support for Mary and recognised Mary's infant son James as King of Scotland.