Prior to any significant degree of bilingualism in Ireland, Irish surnames and place-names were phonetically represented, sometimes with reasonable accuracy, but rarely the same way twice. In earlier records Mac An Bhreitheamhan (sometimes - Breithiunaigh) was variously represented as Macavrehan, Mac a'brehon, MacAbrehon, M'Brehowne, M'Brehan, M'Ebrehowne, mc Ebryhowne, M'Evrehowne, M'Evrehon, M'Inbrehone, M'Evrehoona, mc Breghowne etc. When it was understood that breitheamh meant "a judge, an arbiter", the difficult Mac an Bhreithiun was frequently replaced by the English surname Judge. Others had their names anglicised Brehony, and more rarely Brehon. The majority, however, became Judge - by imposition or by desire.
"In speech the emphasis was on breh, not on A, but the Anglo-Norman clerks who kept most of the official records, being unaware of this, would be misled by the written word and so almost inevitably transcribed it as Mac Abraham" (Mac Lysaght's More Irish Families). And when the Mac was dropped, it became Abraham, a totally separate Jewish surname that had been in Ireland since the 13th century.
An early sighting of Mac an Brethemhnaigh was in Annala Connacht for the year 1463. The intended ollav for Muintir Maelruain - the name of a tribe divided into the families of Mac Dermot of Moylurg, Mac Dermot Roe, Mac Dermot Gall, and Mac Donough belonged in Tirerrill - was Conor Mac an Brehon who died that year after a long sickness. Tirerrill names a barony of Co Sligo, and it was in this barony in the Census of 1659 that Mc Brehuny was listed among the principal Irish families. Variously spelled, this surname is listed 12 times in The Irish Fiants of the Tudor Fiants between 1570 and 1599.
Ballybrehowne/ Ballynabreaghowne/ Ballynembrehoon was the location of ten persons named McEbrehowne - Connor, Oghy, Thomas, Gilladuffe, Owen Grana, Ogh, Nehemais (Giolla na Naomh), Oghney, Shearvreagh, and a second Thomas, listed in Strafford's Inquisition of Co Mayo (1635). Now Ballynabrehon is the name of a townland in the Co Mayo parish of Kilcolman, deriving from Baile na mBreithiun, probably meaning "the town of people named Mac an Bhreithiun".
In 1731 Strafford Eyre, Eyrecourt, wrote to Primate Boulter listing some of his "captures" in refutation of "great endeavours" to question his reputation and honour in discovering convents and houses of friars in Co Galway. He mentions the friars of Dunmore who had removed about five years previously from Clonbrush near Dunmore to Garbally, Patrick Brehon then being prior of the Convent. Brehon who used the alias Johnson, was prior here in 1721, subsequently moving to Galway. However, the provincial Edmund Byrne removed him in 1723, and Brehon, believing himself to have been badly treated, made bitter complaint. Some years later he was in trouble with the bishop of Clonfert. One would have assumed that he had sufficient trouble dodging the "priest hunters" besides opening up another "front". Small wonder that he was considered "a friar of the militant type".
In the current telephone directories there are 40 entries of Abraham in Co Cork, but largely in Leinster. Brehon has seven entries, five being in the 04 area, and there are 49 Brehony entries, predominantly in Connacht and Donegal. Judge is listed 265 times. Apart from the Dublin 01 area, they are predominantly in the 04 area - Monaghan down to Wicklow, as well as being very numerous in Cos Sligo and Donegal.
In 1749, Samuel Judge entered the Quaker school at Ballitore, Co Kildare, the same year as James Napper Tandy. Taylor and Skinner's Maps of the Roads of Ireland (1778) shows three Judge residences - at Ballybrickuck, east of Athlone, and at Ballysheil, Co Offaly.
Judge holdings shown in Owners of Land of One Acre and Upwards (1876) are Celbridge, Co Kildare (six acres); 371 acres in Co Offaly, and 471 in Co Westmeath. There were Brehon holdings of 215 and 516 acres at New Ross, Co Wexford. A will of 1788 mentions one Edward Brehon, New Ross, inn-holder.