The medieval Irish lineage of Bermingham (in the sixteenth century, sometimes written Brimegham) was a branch of a knightly family resident at Birmingham in England. The first to appear in Ireland was Robert de Bermingham, to whom Earl Richard "Strongbow" granted the Irish kingdom of Offaly. Although Robert left only a daughter and heiress Eva, wife of Gerald fitz Maurice (FitzGerald), he seems to have divided Offaly with a brother, perhaps the William who occurs circa 1176, the latter receiving the northern part, known as Tethmoy (Tuath Dha Mhuigh), in modern northeastern County Offaly. Tethmoy descended to Piers de Bermingham (d. 1254), the real founder of the family in Ireland, and from whom they derived the Irish surname of "Mac Feorais." Piers participated in the occupation of Connacht by Richard de Burgh after 1225, receiving the territories of Dunmore (County Galway) and Tireragh (County Sligo), while his second son Meilir received a separate enfeoffment of Athenry, where he founded a walled town and a Dominican friary. Piers’s heir was his grandson, Piers fitz James de Bermingham of Tethmoy, celebrated by the colonists as a great warrior against the Gaelic Irish, but infamous in history for his treacherous massacre (1305) of the O’Connors of Offaly, who were his guests. His uncle Meilir married Basilie de Worcester, heiress of the great Tipperary baronies of Knockgraffon and Kiltinan, and these lands were to be the subject of complicated exchanges, difficult to disentangle, between their son and heir, Piers fitz Meilir of Athenry, and his cousins of Tethmoy. Another son of Meilir, William, was archbishop of Tuam from 1289 to 1314.
Piers of Tethmoy’s son, John de Bermingham, as a reward for defeating Edward Bruce at Faughart in 1318, was created earl of Louth in 1319, with a grant of liberty authority over that county, and was chief governor of Ireland from 1321 to 1323. Resentment against his rule in Louth, with which he had no hereditary links, led to his massacre, along with his followers and many of his Connacht kinsmen, by the local gentry in 1329. His brother Sir William, who inherited his lands, was accused in 1331 of plotting with the first earl of Desmond and others to divide up Ireland between them and make Desmond king. He was imprisoned with his son Walter (d. 1350) by the new English governor Sir Anthony Lucy, and hanged in 1332. Walter was released, pardoned, and reinstated, becoming chief governor of Ireland (1346-1349), in which capacity he made a last, briefly successful attempt to reestablish the royal authority in Connacht. The direct Tethmoy line ended with his son, another Walter, in 1361. Most of Tethmoy was retaken by the O’Connors, while a collateral line of Berminghams, rejecting royal authority and the claims of the Preston family, heirs of Walter’s sister, established an autonomous Gaelicized lordship in the adjacent lands of Carbury (County Kildare), which lasted until 1548. They figure through the fifteenth century alternately as ravaging Meath in company with the O’Connors and as allies of the English against them, while succession to the lordship passed in the Gaelic manner by "tanistry" between several lines.
Richard de Bermingham of Athenry (d. 1322), son of Piers fitz Meilir, was later remembered for his great defeat of the Gaelic Irish of Connacht at Athenry (1316); he was, however, married to a Gaelic wife, the mother of his successor Thomas (d. 1375). During the latter’s time the Bermingham lands in Connacht, now concentrated in the hands of the Athenry family, suffered severe losses: Tireragh was recovered by its Gaelic lords, the O’Dowdas, while the O’Kelly s— who inflicted a severe defeat on Thomas in 1372— subsequently occupied much of the Athenry territory, reducing the Bermingham lordship to Dunmore and a small area around Athenry. Knockgraffon and Kiltinan, after being held by a junior branch, reverted briefly to Thomas’s son, the long-lived Walter (d. 1431), before being sold to the Butlers in 1410. Walter of Athenry, who served as sheriff of Connacht, was knighted by Richard II at Waterford in 1394, but thereafter the family’s links with the English administration disappear. On the death in 1473 of Walter’s son Thomas, the latter’s son and namesake had to contend in turn with two cousins, one of whom—the son of a Richard who had died in 1438—succeeded in ousting him for a year. It is obvious that the lordship of Athenry in spite of being recognized as a peerage dignity by the Crown—perhaps a recognition of the former importance of the Bermingham name— was starting to pass by Gaelic modes of succession. After the death of the younger Thomas’s son Meilir Buidhe (the yellow-haired) in 1529, the lordship passed to a Thomas whose descent is unclear, and then to Richard (a descendant of the Richard of 1438), who consolidated his position by killing his namesake, Meiler’s son, and whose descendants continued as lords of Athenry.
In the thirteenth and fourteenth centuries, many other branches of the lineage existed in Connacht, Meath and Tipperary, many of whom later died out or were reduced to insignificance. In the fifteenth, a member of the Carbury branch acquired by marriage the hereditary chief sergeantship of Meath and lands in that county: his grandson Patrick Bermingham of Corbally (d. 1532) was Chief Justice of the King’s Bench in Ireland, a post previously occupied (1474-1489) by a Philip Bermingham, perhaps from a branch that settled at Baldongan in County Dublin.
