From Irish Pedigrees; or the Origin and Stem of the Irish Nation by John O'Hart
THE O'h-Aichir, O'Haithchir, O'Hehir, Hehir, and Hare, are all one family, of the Dal-Cas sept. They were formerly chiefs of Magh-Adhair, a district in the County Clare, lying between Ennis and Tulla; but, having been driven thence by the Hy-Caisin in early times, they settled in the country now forming the barony of Islands, where they became possessed of the districts of Hy-Cormac and Hy-Flanchada, according to O'Heerin:—
"Of the race of Eoghan of Orior-Cliach,
Are the Hy-Cormac of the smooth fair plain;
The fertile land is the lordship of O'Hehir,
The ancestor of powerful chiefs.
The head of many a powerful house
Are of the noble clan of O'Haithchir;
They govern Hy-Flanchadha of hospitable mansions,
And are valiant and well-armed Fenians."
The district of Hy-Cormac, comprised the Callan mountains, and extended to the town of Ennis. In A.D. 1094, Amhlaobh O'Hehir was slain; and, in 1099, Donogh O'Hehir, lord of Magh-Adhair, died. This Magh-Adhair was the place of the inauguration of the O'Briens as princes of Thomond, and the O'Hehirs always assisted at the ceremony.
In 1197, died, Gilla-Patrick O'Hehir, Abbot of Innisfallen, in the 79th year of his age; and, in two years afterwards, Auliffe O'Hehir, a religious of the same establishment. By the late Dr. O'Donovan, the "O'Hares" are set down as a tribe of the Hy-Feigeinte, of the race of Eoghan-Mór.
We believe this family is now (1887) well represented by various gentlemen in the County Clare.