Argyll held a unique position within the islands of Britain. Though at first sight appearing similar to other members of the early modern European aristocracy, he replicated and in certain ways surpassed the power of some contemporary ruling sovereigns. He was the most powerful nobleman in the sixteenth-century Atlantic archipelago with a substantial independent military and naval force at his disposal. What made Argyll distinctive was the unusual nature of his power and not solely its quantity. Whilst remaining a loyal subject of the Scottish crown, the earl wielded semi-sovereign authority within his own ‘country’. This unusual status allowed him to operate successfully in the complex of polities and cultures that existed in the islands of Britain.

To the Gaelic poets, Argyll was ‘King of the Gael’, while a Scots commentator summarised his status as ‘regal within himself’. The 5th earl was a semi-sovereign prince who maintained his own court through which he ruled the heartland of Argyll and the Western Highlands and Islands. He held the temporal sword in his hand and could wield it as he chose, as one of his subordinate chiefs had reminded him. The earl had no hesitation in exercising regalian rights, issuing proclamations and letters of legitimation, granting licences to travel, giving marriage dispensations and in practice ennobling his subordinates. In his correspondence, the 5th earl employed the language and terminology that modern historians associate exclusively with royalty, using the royal ‘we’ and referring to ‘our awin proper persone’.