He first met Prince Charles during the 1745 Rebellion at Callendar House on 14 September. The decision to join the Jacobite army surprised many; it has been suggested one reason for doing so was pressure from his wife's family but he later told Argyll; "...I was starving, and...if Mahommed had set up his standard...I had been a good Mussulman for bread, for I must eat."