Classes of Irish Surnames

I.—Surnames of this class are formed by prefixing Ó or Ua, grandson, descendant, to the genitive case of a native Irish personal name, as Ó Briain, des. of Brian; Ó hAodha, des. of Aodh; Ó Néill, des. of Niall (see p. 15). This is our oldest and most numerous class of surnames. For declension, see p. 25.

II.—Surnames of this class are formed by prefixing Ó or Ua, grandson, descendant, to the genitive case of a name of foreign origin, as Ó Bruadair, des. of Bruadar; Ó Dubhghaill, des. of Dubhghall; Ó hArailt, des. of Harald. Surnames of this class are mostly of Norse and Danish origin. See p. 16, and for declension, p. 25.

III.—Surnames of this class are formed by prefixing Ó or Ua, grandson, descendant, not to the personal name of the ancestor, but to the genitive case of a word indicative of his trade, profession, rank, or occupation, as Ó Gobhann, des. of the smith; Ó hÍceadha, des. of the healer (see p. 15). Only a comparatively small number of surnames belongs to this class. For declension, see p. 25.

Note.—The above three classes comprise all genuine surnames in Ó or Ua. Many apparently Ó-surnames are merely corruptions of surnames in Mac- or Mag- (see p. 32).

IV.—Surnames of this class are formed by prefixing Mac or Mag, son, to the gen. case of a native Irish personal name, as Mac Aodhagáin, son of Aodhagán; Mac Cárthaigh, son of Cárthach; Mag Uidhir, son of Odhar (see p. 15). This is an old and numerous class of surnames. For declension, see p. 25.

V.—Surnames of this class are formed by prefixing Mac or Mag, son, to the genitive case of a name of foreign origin, as Mac Íomhair, son of Ivor; Mac Maghnuis, son of Magnus; Mac Fheórais, son of Piers; Mac Sheóinín, son of little John. Surnames of this class are mostly of Norse and Norman origin. See pp. 16, 19.

VI.—This class comprises surnames of Welsh origin, formed by prefixing 'ab' or 'ap', son, to a Welsh personal name (see p. 17). Only a few surnames belong to this class. For declension, see p. 26.

VII.—Surnames of this class are formed by prefixing Mac, son, not to the personal name of the ancestor, but to the gen. case of a word indicative of his trade, profession, rank, or occupation, as Mac an Bháird, son of the bard; Mac an tSaoir, son of the craftsman; Mac an Ridire, son of the knight (see p. 15). Families bearing surnames of this class may be of either Irish or foreign origin.

VIII.—This class comprises all patronymic surnames of foreign origin in which the father's name appears in its simple and unaltered form, without prefix or desinence (see pp. 17, 19). The great bulk of Anglo-Norman patronymic surnames belong to this class. For declension, see p. 26.

IX.—This class comprises Irish descriptive adjectives which have supplanted the real surnames (see p. 21). For declension, see p. 26.

X.—This class comprises surnames in -ach, -each, indicative of nationality, place of origin, fosterage, &c. (see p. 21). They may be either substantives or adjectives. For declension, see p. 26.

XI.—This class comprises foreign surnames of local origin (see pp. 18, 19, 20). This class is very numerous. For declension, see p. 26.

XII.—This class comprises occupative and descriptive surnames of foreign origin (see pp. 18, 19, 20). This class is very numerous. For declension, see p. 26.

XIII.—This class comprises Irish surnames formed from the gen. case of place of residence, or some peculiarity (see p. 21). They were not originally surnames in the strict sense, but took the place of real surnames which are now lost. For declension, see p. 26.

XIV.—This class comprises alternative forms of surnames (see p. 21). For declension, see p. 26.