In 1354, though in exile and without control of his ancestral lands, John, the MacDougall heir, quitclaimed any rights he had over Mull to the Lord of the Isles. When Robert's son David II became king, he spent some time in English captivity; after his release, in 1357, he restored MacDougall authority over Lorn, effectively cancelling Robert's grant to the MacRory. The 1354 quitclaim, which seems to have been an attempt to ensure peace in just such an eventuality, took automatic effect, splitting Mull from Lorn and making it subject to the Lordship of the Isles.