Flight of the Heron by D. K. Broster

Ewen Cameron, a young and handsome Highland laird devoted to the Jacobite cause, takes the English army captain Keith Windham prisoner on the eve of the Jacobite uprising of 1745, and learns that there is a prophecy that will bring them together five times. Captain Windham is a professional soldier who has grown cynical, believing that it is better to reject any attachments before they bring disappointment. He does not expect much of his captor, but is surprised at the honourable and generous treatment he receives. With each meeting, the bond between them grows, but what will become of them after Culloden, when Captain Windham is expected to take part in the savage repression of the Jacobites?