Clandonnell along with the ancient districts of Glenconkeyne, Killetra, and Tomlagh, comprised the former barony of Loughinsholin, with Clandonnell forming the northern part reaching as far south as Maghera.
[1][2] Clandonnell derives its name from the Clann Domhnaill Donn na Banna a branch of the Clandeboye O'Neills.
[3] The most celebrated descendant of Donnell Donn was his great-grandson Brian Carrach O'Neill who is stated as being the last lord of Loughinsholin.
[4][5] His stronghold was based at the crannog at Inishrush, which is also known as the Green Lough.
The latter statement meant that the area was amongst the most impenetrable parts of Ulster.