He and his brother Peter Menteith accompanied the English King as esquires on his expedition to Flanders in 1297.
He supported King Robert the Bruce in his initial attempt to seize power following the deposition of John Balliol.
Menteith was committed to Abergavenny Castle; he died a prisoner before 13 March 1308/09, when John de Hastings had licence "to demise to Margery, late the wife of Alan, earl of Menteth, for her life, the manor of Wotton..."[1] Menteith was succeeded in his Earldom by his son Alan II, Earl of Menteith, who was then a minor.
[3] They had two sons, one of whom, Alan, succeeded his father as Earl when a minor.
[4] Balfour Paul, Sir James Scots Peerage IX vols.