The practice which prevails in Ireland of using two names appears to be largely traceable to the influence of ancient legislative action.
 By a Statute of 1366, it was provided, inter alia, that ‘every Englishman do use the English language and be named by an English name, leaving off entirely the matter of naming used by the Irish’; and in 1465 [5 Ed. IV, cap. 3] a law was passed enacting “that every Irishman that dwells betwixt or amongst Englishmen in the County of Dublin, Myeth, Vriell, and Kildare .. shall take to him an English surname of one town, as Sutton, Chester, Trym, Skryne, Corke, Kinsale; or colour, as white, blacke, browne; or arte or science, as smith or carpenter; or office, as cooke, butler ...”.
 In many cases, where English and Irish names are used interchangeably, they are translations from one language into the other or translations of words similar in sound.  [21]
 The following may be cited as examples: [English form:] Bird; [Anglicised Irish Form:] Heany; Henehan; Henekan; McEaney; [Irish Words:] ean (ean) - a bird (p.21)