[4] Ailill is recorded in the king lists of the Book of Leinster, the synchronism's of Thurneysen, Boyle, and the Annals of Clonmacnoise.
[7][9] For a two-hundred year period beginning in the late fifth century, the native Dál Birn kings were temporarily displaced by an allied Corcu Loígde dynasty, which ruled Osraige until being overthrown.
Several Corcu Loígde kings are recorded as being periodically slain by the native inhabitants of Osraige until the re-establishment of the Dál Birn.
Dál Birn descendants remained in control of parts of Osraige even after the Norman Invasion of Ireland, with the continuation of the Mac Giolla Phádraig lordship in Upper Ossory.
This senior Dál Birn lineage historically remained the most visible and possessed an original portion of Osraige through the death of Bernard FitzPatrick, 2nd Baron Castletown in 1937.