As a frontier territory of Connacht it was a saor-túath (territory exempt from tribute) under several Irish dynasties over time, but mostly under a branch of the O'Connor dynasty called the Clann Aindrias or O'Connor Sligo The O Conor Sligo (Ó Conchobhair Sligigh) were a branch of the Ó Conchobhair royal family who were Kings of Connacht.

Tírechán's seventh century Life of Patrick states that Cairbre was cursed by the saint, at the hill of Tara, that none of his descendants would be High King.

Cairbre's descendants at an early date controlled a larger Cairpre Mor grouping which stretched from Sligo to Westmeath, taking in Leitrim and parts of Fermanagh (such as Tuatha Ratha or Magheraboy) and Longford (North Tethbae).

This territory, under the shadow of Benbulbin (from the Irish: Binn Ghulbain), is where Conall Gulbain set out to conquer Tír Chonaill, modern Donegal.

In 1051 AD Cathal, son of Tighearnain, lord of Breifne, went upon a predatory excursion into Eabha, and demolished Dun-Feich, where fifty persons were slain, and whence seven hundred cows were carried off.

1214.7 - The territory of Carbury County Sligo, the possession of Philip Mac Costello, was preyed by Ualgarg O'Rourke, who carried off a number of cows.

1257 AD the Battle of Creadran Cille was fought between the Normans and Irish at Ros Ceite (Rosses Point).The family fell out with the de Burghs later and were divested of their Connacht lands.

Lines of the original Cenel Cairbre Drom Cliabh survived quasi-anglicised as 'Stone' (from O'Mulclohy) in Carbury and the O'Flanagan's of Tuatha Ratha, in the barony of Magheraboy, Fermanagh.

The Sligo river carried off to the great sea Men's blood with their flesh, They utter paeans over Eba Round the head of Eogan Bél.