On the recommendation of Dr Alexander Cunningham, a younger son of Sir William Cunningham of Caprington,
Ayrshire, Lumisden became private secretary to
Charles Edward Stuart shortly after his arrival in Edinburgh. He accompanied the prince throughout the campaign, and was present at the
battle of Culloden. On the eve of the battle the prince's aide-de-camp wrote to
Ewen MacPherson of Cluny, asking him to take particular care of Lumisden and
Thomas Sheridan, "as they carry the sinews of war". After the battle Lumisden obeyed the order to rendezvous at
Fort Ruthven, where a message from Charles Edward on 17 April warned all to look after their own safety. He was included in the Act of Attainder, and, after staying in Highland fastnesses for four months, went to Edinburgh disguised in a black wig, as the liveried groom of a lady who rode pillion behind him on a horse. After lurking in concealment in his father's house till October, he accompanied to London, as a poor teacher, the king's messenger, who had been in Scotland citing witnesses for the treason trials. ==Exile==