The territory of Route was originally part of Twescard, which was a county of the Earldom of Ulster, that at its height stretched from the Glens of Antrim to Inishowen. The murder of the Earl of Ulster in 1333 saw the Irish chiefdoms rebel and the Earldom of Ulster eventually collapsed, with it gradually almost all falling under Gaelic control. By the 1460s, the de Mandevilles who held manors in Twescard, decided to abandon them and sold their land to the MacQuillans, who according to the Annals of Ulster were already in the region warring with the O'Cahans as far back as 1442.