After the Battle of Harlaw, younger brother Robert carried out his oath to his older brother, Alexander, and changed his name to Alexander and married his elder brother's fiancée, Elizabeth de Keith, thus ending the feud of their forefathers. He is also believed to have exchanged swords with the son of Red Hector in token of peace between their families. Sometime later he led the delegation which negotiated the release of James I from the hands of the English, for which he was knighted.

In 1414 he was regranted the lands of Forglen which were his grandfathers.  He was appointed Governor of burgh of Aberdeen 1439; in 1446 he was granted the lands of Learney.  He was second 4th Laird of Drum and succeeded his brother of same name who died in the Battle of Harlaw.  In late 1411 he married Elizabeth Keith, daughter of the Marischal of Scotland.

In his later years he built St. Ninian's Chantry in St. Nicholas' Church, Aberdeen, and in 1457 was buried there with his wife in Drum's Aisle. Part of his carved tomb was subsequently moved to the Chapel at Drum, but the couple's stone effigies and their memorial brass, a most unusual feature in Scotland at this date, can still be seen at St. Nicholas' Church.