[3] Most contemporaries described him as an amiable man with a facility for getting on well with people of all social ranks: it was noted that Perth "never properly learned the English language, but invariably used broad Scots".

[6] Although dismissed by Walpole as a "silly horse-racing boy", Perth was recognised by the government as one of the more committed Jacobite sympathisers,[7] particularly as their reports identified his influence over "a Considerable Number of Barrons and Gentlemen of the Name of Drummond".

[8] In 1740, as French statesmen began to consider the possibilities of supporting the Jacobites as a counter to British interests, he formed a pro-Stuart "Association" with Lord Lovat, Lochiel and a number of other gentry.

[11] However, further men raised in the north-east joined Perth's regiment at Edinburgh; these included a group of volunteers from Aberdeen led by a lawyer, Roger Sandilands,[12] and the 'Enzie' battalion from Banffshire under John Hamilton of Sandistoun, the Duke of Gordon's estate factor and a veteran of 1715.

There was initially an arrangement that the two men would take command on alternate days;[14] although in practice this meant they rarely interfered with each other's decisions, James Maxwell of Kirkconnell claimed that Murray was unhappy with serving under someone "certainly much inferior to him in years and experience".

Murray's frustrations came to a head at the siege of Carlisle, where he also suggested that as a Catholic Perth was a politically unwise choice of army commander for an English campaign.

Perth had previously written to the Jacobite Tory MP for Denbighshire Watkin Williams-Wynn authorising him to recruit for the rising,[20] and at Derby, where the Council voted to retreat to Scotland due to a lack of visible English and French support, he was one of the few members to suggest they march to North Wales.

[14] On the march north he was sent ahead to Scotland, accompanied by Murray of Broughton's Hussar regiment, to bring reinforcements; Perth's group had to turn back to Kendal after they were attacked by militia.

Perth had always been said to have had a delicate constitution following a childhood accident;[5] the campaign had taken a high physical toll on the participants and some accounts suggest that by this point he was unwell and was being carried by retainers.

[25] In a period when the Jacobite sympathies of many were the result of a complex mixture of political, religious, familial and other local factors, Perth's motivation appeared relatively straightforward to contemporaries: recording his death, Elcho wrote that "he was a very brave and gallant man and entirely devoted to the House of Stuart".