In 1220 Farrell Magauran was killed by the O’Rourkes. This set a precedent, the most common reason for the family appearing in the annals was when they were killed by some of there more powerful neighbours. Although in 1248 they managed to kill Hugh Maguire. In 1272 Donnachadh Magaurans was killed by his brother Thomas. In the late 1300s Brian, the chief had a bardic (poetry) school at the foot of Cuilceagh. His son Thomas commissioned a scribe to write the Duanaire Mheig Shamhradhain (the book of the Magaurans) which is preserved in the National Library.
In 1431 they were again in conflict with the Maguires when they murdered John Maguire, as a result of this the Maguires invaded Tullyhaw and burned Ballymagauran (a few mile west of Bawnboy) their headquarters. In 1455 the Maguires again burned Ballymagauran. The O’Reillys burned it in 1485. The Maguires invaded Tullyhaw in 1512, but this time the O’Reillys came to their aid and defeated the invaders. In the same year Thomas sough the Maguires help in an internal power struggle.
Tullyhaw finally became part of Ulster permanently in 1584 when Sir John Perrot shired Brefnie and created the County of Cavan. The influence of the Magaurans as a ruling family lasted longer than most Gaelic rulers, protected by the mountains and inhabiting an area more suitable for pastoral farming, they continued to elect a chief well into the 1800s. Lewis’s Topographical Dictionary, published in 1837 record that "Tullaghagh, in the mountain district between the counties of Fermanagh and Leitrim, generally known as "the kingdom of Glan," ...... or the country of the Mac Gaurans. To this isolated district there is no public road, and only one difficult pass ...... is densely inhabited by a primitive race of Mac Gaurans and Dolans, who intermarry and observe some peculiar customs ; they elect their own king and queen from the ancient race of the Mac Gaurans, to whom they pay implicit obedience. Tilling the land and attending the cattle constitute their sole occupation ; potatoes and milk, with, sometimes oaten bread, their chief food". This description of life in the Glan, with the exception of the reference to potatoes, could have been written 250 earlier when a lot of Ireland was still ruled by Gaelic chiefs. Over 200 year after the collapse of the Gaelic political system, with the industrial revolution in full flight, the Magaurans were still living the life of Gaelic chiefs in the mountains of Tullyhaw.