in 1715 he took an active part in proclaiming james francis edward stuart (the old pretender) on the death of queen anne, for this he was tried at launceston and acquitted and welcomed by "bonfire and by ball" from thence to the land's end. for his actions he was created marquess of trelissick (also called marquis of trelessick) in the jacobite peerage on 20 june 1715.