The process of dragging the old Gaelic surnames into English was messy and surprisingly long drawn out. As late as the 19th century, some parish registers still provide a time-lapse record of the changes happening.
In west Cork, children baptised as "Fowlow" (Ó Foghlú, from foghlaí, "a robber") in the 1820s become "Fowly" in the 1830s and finally "Foley" in the 1840s. In Leitrim, members of the same family are first "Breheny" (from Mac an Bhreitheamhan, "son of the judge"), then "Judge" and finally, God help us, "Abraham", mangled out of "McAbrahan".
These two examples illustrate the most common ways surnames were anglicised, phonetic transcription and translation, both almost always treating the O or Mc prefix as irrelevant. The results could be rough and ready, approximate versions of what a record-keeper thought he heard or imagined he understood.
The stretch from Ó Murchú ("grandson of the sea-hound") to "Murphy" has always seemed a phoneme too far to me. Because any Anglophone record-keepers who knew Irish had only a smattering, mistranslation was the rule, not the exception. Mac Conraoi (west Galway), Mac Fhearadhaigh (Oriel), Ó Maol Conaire (Roscommon), and Ó Conraoi (east Galway) all ended up as "King" in English, simply because they contain elements that to an untutored ear sound like rí, "king".
But the ultimate insult to the old surnames was transposition. A lazy or exasperated record-keeper would give up any pretence of translation or phonetic transcription and just pick an English surname that bore some resemblance to the Irish original. The resemblance was often remote: "Bradley" for Ó Brolacháin; "Harrington" for Ó hIongardáil; "Holland" for Ó Maol Challann; "Davenport" for Ó Donnuartaigh.
The three centuries before independence saw a great influx of English and Scottish families, among them, no doubt, plenty of actual Bradleys, Harringtons, Hollands and Davenports.
As guides to ethnic origins, surnames in Ireland can be very treacherous indeed.
