He married Catherine Stewart, an illegitimate daughter of King James IV of Scotland by his mistress Marion Boyd.
The legal instrument was witnessed by David Beaton, Thomas Erskine of Haltoun, John Tennent, Oliver Sinclair of Pitcairns, Andrew Wood of Largo, and other prominent courtiers.
The lands were immediately granted to Robert Douglas of Lochleven, the husband of the King's former mistress Margaret Erskine.
Robert Douglas subsequently resigned the title to James V on 20 January 1542, withholding only Aberdour Castle.
Morton stated that he was old and infirm and would have been unlikely to survive confinement in Inverness away from the comfort of East Lothian, and was compelled by his 'just dredour' (rightful fear) of the King with his 'menacing' and messages with 'boastful words'.