James's father, Darnley, was murdered on 10 February 1567 at Kirk o' Field, Edinburgh, perhaps in revenge for the killing of Rizzio. James inherited his father's titles of Duke of Albany and Earl of Ross. Mary was already unpopular, and her marriage on 15 May 1567 to James Hepburn, 4th Earl of Bothwell, who was widely suspected of murdering Darnley, heightened widespread bad feeling towards her. In June 1567, Protestant rebels arrested Mary and imprisoned her in Loch Leven Castle; she never saw her son again. She was forced to abdicate on 24 July 1567 in favour of the infant James and to appoint her illegitimate half-brother, James Stewart, Earl of Moray, as regent.