Known in charters as Alexander "Senescalli" (Latin for Steward), first noted when, on 14 August 1370, he issued letters patent from Ruthven Castle undertaking to grant protection to the Bishop of Moray and all of his lands, men and property in Badenoch. His father, Robert the Steward, had acquired the lands of Badenoch probably from Euphemia, Countess of Moray who had become his second wife. Robert had a petulant relationship with his uncle, King David II of Scotland. In 1368 he and his sons were required by David's parliament to take an oath that they would keep their undisciplined followers in check—later that year, Robert and Alexander were imprisoned in Loch Leven Castle possibly as a result of these oaths having been broken. Following Robert's accession to the throne, Alexander was formally made Lord of Badenoch on 30 March 1371.