For background on how the map was made (and its flaws), see the relevant blog entry.
|Kirwan||numerous: all areas except Ulster, especially the South East, Louth. The Irish is Ó Ciardhubháin, ciar-dhubh = jet black. An erenagh family of Louth and later one of the "Tribes of Galway". IF & SGG.|
|O Ciardhubháin||rare: Ir.Lang. See Kirwan.|
|Ó Ciardubháin||Kirwan: an-líonmhar: go príomha i ndeisceart Laighean & Port Lairge. Airchinnigh i Lú ar dtús iad, ach is mar cheann de "Threabhanna na Gaillimhe" is mó atá trácht orthu. Ciar-dubh = fíor-dubh. Litriú nua: Ó Ciarubháin.IF.|
DEDs where Kirwan and a second surname are found together