Bermingham was the son of Francis Bermingham, 14th Baron Athenry, by his first marriage to Lady Mary Nugent, daughter of Thomas Nugent, 4th Earl of Westmeath. He was elected to the Irish House of Commons as Member of Parliament for Galway County, sitting between 1745 and 1750, when on 4 March 1750 he succeeded his father as Baron Athenry and became a member of the Irish House of Lords. He was invested as a member of the Privy Council of Ireland, but was ejected from it in 1767 by Lord Townshend, the newly arrived Lord Lieutenant of Ireland, who wished to make a "clean sweep" of the Irish administration, removing all those he regarded as corrupt or inefficient. On 23 April 1759 Lord Athenry was created Earl of Louth in the Peerage of Ireland, a title previously held by John de Bermingham, 1st Earl of Louth, a cousin of his remote ancestor Rickard de Bermingham.
Marriages and childrenEdit
He married, firstly, Jane Bingham, the daughter of Sir John Bingham, 5th Baronet. and Anne Vesey, in November 1745. He married, secondly, Margaret Daly, the daughter of Peter Daly and Elizabeth Blake, on 10 January 1750. He died in 1799 and is buried in the Dominican Friary at Athenry, founded by his ancestor in 1241. His property was divided between his three daughters and their families. He left no surviving male issue, so his earldom became extinct. The barony fell into abeyance and became dormant : among those who unsuccessfully claimed it after him were his grandson Thomas Sewell, and the family of John Birmingham.
His daughters were-
- The Peerage of England, Scotland, and Ireland: The peerage of Ireland ( W. Owen [and 2 others], 1790), pp. 93-95.
- The Peerage of England, Scotland, and Ireland: The peerage of Ireland ( W. Owen [and 2 others], 1790), 93-95.
- History of Galway, James Hardiman, Galway, 1820
- The Abbey of Athenry, Martin J. Blake, Journal of the Galway Archaeological and Historical Society, volume II, part ii, 1902
- The Birmingham family of Athenry, H.T. Knox, J.G.A.H.S., volume ten, numbers iii and iv, 1916–17.
- The Birmingham chalice, J. Rabbitte, volume 17, i and ii, 1936–37