In ancient times, people of Donegal spoke of "west of the mountain" and "east of the mountain." The mountain was the long range that was cut through by Barnesmore (Big Gap) on the Ballybofey-Donegal Town road.
In the thirteenth century the O'Boyles were in control of the territory west of the mountain. This territory consisted of the barony of Banagh in the region of Killybegs and the barony of Boylagh to the north. This latter coincided with what today is called the Rosses. It is bounded on the south by the Gweebarra river and in the north-east by the Gweedore river.
With the coming of the Mac Sweeneys in the fourteenth century, the O'Boyles lost control of Banagh. In that century Murchadh Mear MacSuibhne bequeathed Tir Boghaine (Banagh) to his grandson, Dubhghall. In the fifteenth century there was another incursion of the Mac Sweeneys, this time from north Connacht.
The chief stronghold of the Mac Sweeneys in this area was Rahan Castle, on St. John's Point, near Dunkineely. St. John's Point is a peninsula six miles long and rarely more than half a mile wide. On the west coast are still to be seen some of the remains of Rahan Castle.
Under the year 1524, the Four Masters wrote: "Niall Mór MacSuibhne of Tir Boghaine died, after Unction and Penance, in his own fair castle at Rahan, on the fourteenth of December."
Niall was buried within the precincts of the Franciscan church at Ballysaggart on St. John's Point, which his father, Eoghan Mac Sweeney, had built. His grave was marked by a remarkable tombstone, which is now at St. Mary's Church in Killybegs. In shape and design it is somewhat similar to another Mac Sweeney tombstone at Doe Castle.
For the year 1588 the Four Masters record an internecine battle of the Mac Sweeneys of Banagh. It was fought on an island called Doirinis off the west coast, near Ardara.
The last of the name to reign in Banagh was Donnchadh Dubh, who, in 1602, submitted to the English. He got a grant, or rather re-grant under English law of 2,000 acres of his own land. We have seen that the last Mac Sweeney chief of Doe Castle benefited in a similar way under the plantation. Donnchadh Dubh died in 1632.
In the nineteenth century (1844) the stones of the castle at Rahan were used to build in Killybegs the parish church, which was dedicated to St. Mary of the Visitation.
In the present century the outstanding Mac Sweeney of West Donegal was Gen. Joseph Sweeney, who was born in 1897 at Burtonport.
Joe was educated at St Eunan's College, Letterkenny, and at St Enda's, Dublin, under Patrick Pearse. He later studied at U.C.D. and U.C.G. Joe joined the Irish Volunteers in 1914 and, still in his teens, served with his company in the G.P.O. in Easter Week, 1916. In 1917 he was appointed Commandant of the Donegal Battalion of the I.R.A.
He was Sinn Fein M.P. for West Donegal, 1918-1922, and T.D., 1922-'23. He was later G.O.C. of Western Command and Curragh Command. He retired from the Army in 1940, and became Area Officer of the Red Cross Society, 1950-'56.
The above was taken from 'The Mac Sweeneys' by Fr. David OFM Cap.