Brian Carrach MacDonnell, the younger brother of James and Sorley, gained from the eclipse of his older brothers in the year following Glentaisie. His alliance with Shane made him the most powerful MacDonnell in the Glens and Route until Shane's assassination by his nephews in 1567, and his own death the following year. The death of James of Dunnyveg in captivity at Castle Crocke on 5 July 1565, within months of the battle, left the lordship of the Glens nominally in the hands of his sons Archibald MacDonald, 7th of Dunnyveg and Angus MacDonald, later 8th of Dunnyveg, Sorley's nephews.
Sorley Boy, previously simply James's Seneschal of the Glynnes and Route, acquired considerable authority as the last remaining MacDonnell of his generation still resident in Antrim in the years after 1567. After leading a protracted twenty-year struggle to defend the Glens and Route against the O’Neills of Clandeboye, the MacQuillans and the English, Sorley had his authority confirmed with an unexpectedly decisive victory at the battle of Orra in 1583. Shane O'Neill's defeat of the MacDonnells at Glentaisie had cleared the way for the elevation of Sorley and his descendants by removing his eldest brother James of Dunnyveg, proper inheritor of the lordship of the Glynnes and Route and claimant to the prestigious lost title of "Lord of the Isles."