The principal surnames for each county is listed, they are in order of the numerical strength in which they occur. The figure after the surname is the number of entries in the birth index for 1890.

The estimated number of persons of each surname can be ascertained by multiplying the figure by the average birth rate, which for that year was 1 in 44.8 persons.

Although Murphy· is the most numerous surname in the country at large, it does not occupy the leading position in many of the counties. In Leinster in the counties of Wexford and Carlow Murphy· is first.

In the counties of Dublin. Louth and Wicklow. Byrne· is first, whereas in Kildare and Offaly Kelly· is first.

In Longford and Meath, Reilly· is first, in Kilkenny, Brennan, in Laois Dunne·, and in Westmeath Lynch·.

In Munster, Sullivan· is the predominant surname in Cork and Kerry, followed in Cork by Murphy·. Ryan· heads the list in Limerick and Tipperary, while McMahon· is the leading surname in Clare, and Power· in Waterford.

In Ulster Murphy· is the first surname in Armagh only. In Antrim Smith· is first, in Cavan, Reilly·, in Donegal, Gallagher·, in Down Thompson·, in Fermanagh Maguire·, in Derry, Doherty·, in Monaghan, Duffy·, and in Tyrone Quinn·.

In Connacht, Kelly· takes precedence in Galway, Roscommon, and Leitrim (along with Reynolds), Murphy does not occupy the principal position in any county. Walsh is first in Mayo, and Brennan in Sligo.

Province of Leinster

Murphy 41, Byrne 33, Doyle 32, Nolan 28, Neill 27, Brennan 24, Kelly 15, McDonald 15, Kavanagh 14, Whelan 12, Ryan 10.

Byrne 301, Kelly 194, Doyle 162, Murphy 132, Smith 106, O·Brien 105, Kavanagh 97, Dunne 93, O·Neill 93, Reilly 93, Nolan 89, Connor 82, Walsh 77, Farrell 73, Carroll 71, Ryan 65, Moore 63, Cullen 62, Keogh 60, Murray 60, Whelan 59, Brady 52, Kennedy 51.

Kelly 40, Murphy 34, Dunne 32, Byrne 28, Nolan 20, Connor 18, Smith 18, Farrell 15, Ryan 15, Moore 14, Carroll 13, Neill 13, Bolger 12, Doyle 12.

Brennan 49, Walsh 45, Murphy 35, Ryan 34, Carroll 25, Byrne 22, Butler 22, Maher 21, Dunne 20, Phelan 18, Kelly 17, Neill 17, Power 17, Purcell 17, Brien 15, Shea 15, Delaney, 14, Dowling 14.

Dunne 34, Delaney 30, Conroy 19, Lalor 18, Phelan 18, Fitzpatrick 17, Ryan 13, Carroll 12, Whelan 12, Byrne 11, Kavanagh 11, Kennedy 11, Brennan 10, Kelly 10, Murphy 10.

Reilly 78, Farrell 36, Kiernan 24, Kelly 23, Donohoe 19, Murphy 14, Brady 13, Quinn 12, Smith 12.

Byrne 36, Kelly 30, Murphy 30, Smith 26, Clarke 23, Duffy 21, McArdle 20, Reilly 20, Carroll 19, Mathews 16, Martin 14, Donnelly 13, Farrell 13, Morgan 13, Rice 13, Hanratty 12, McCourt 12, McKenna 12, Boyle 11, Connor 11, Lynch 11, O·Hare 11.

Kelly 34, Dunne 23, Daly 20, Egan 17, Molloy 16, Mooney 16, Carroll 12, Walsh 12, Kenny 11, Murray 11, Dempsey 10, Kennedy 10, Maher 10.

Reilly 53, Smith 30, Lynch 17, Brady 16, Farrell 14, Farrelly 14, Kelly 14, Brien 13, Daly 11, Maguire 11, Duffy 9, Dunne 9, Byrne 8, Connor 8, Mahon 7, Clarke 7, Martin 7, Mathews 7.

Lynch 14, Farrell 13, Reilly 12, Daly 11, Murray 10, Duffy 9, McCormick 9, Walsh 9, Dalton 8, Kelly 8, Smith 8, Byrne 7, Carey 7, Dunne 6, Flynn 6, Leavy 6, Murtagh 6, O·Neill 6.

Murphy 137, Doyle 102, Walsh 56, Byrne 46, Cullen 34, Kavanagh 34, Brien 32, Roche 31, Kelly 30, Nolan 30, Redmond 30, Connor 28, Kehoe 28, Ryan 26, Bolger 25, Whelan 25.

Byrne 87, Doyle 53, Murphy 26, Kelly 25, Kavanagh 24, Nolan 21, Brien 18, Kehoe 16, Lawlor 15, Toole 14, Dunne 13, Farrell 11, Redmond 10.

Province of Munster

McMahon 74, McNamara 61, Moloney 50, O·Brien 47, McInerney 39, Kelly 38, Keane 33, Murphy 29, Griffin 27, Halloran 26, Ryan 23, Lynch 22, Clancey 21.

Sullivan 418, Murphy 390, McCarthy 277, Mahoney 193, Donovan 182, Walsh 143, O·Brien 139, Callaghan 134, Leary 134, Crowley 116, Collins 115, Driscoll 110, Connell 109, Barry 108, Cronin 102, Buckley 100, Daly 97, Sheehan 97, Riordan 94, Kelleher 92, O·Connor 91, Hurley 86, Regan 85, O·Keeffe 84, Harrington 82, Fitzgerald 81, O·Neill 75.

Sullivan 349, Connor 188, Shea 146, Murphy 95, McCarthy 88, Moriarty 74, Fitzgerald 72, Griffin 58, Connell 56, Brosnan 55, Foley 55, Leary 47, Clifford 45, Walsh 45, Cronin 43, Lynch 41, Mahoney 38, Daly 34.

Ryan 91, O·Brien 78, Fitzgerald 58, Sullivan 50, Hayes 45, Walsh 45, Collins 40, O·Connell 39, Murphy 38, Moloney 38, O·Connor 37, Lynch 31, McNamara 31, O·Donnell 28, Ahern 25.

Ryan 277, Maher 74, O·Brien 74, Kennedy 70, Dwyer 64, Hogan 46, Hayes 38, Gleeson 38, Mc Grath 38, Walsh 38, Kelly 31, Lonergan 31.

Power 125, Walsh 97, O'Brien 47, Murphy 35, Ryan 35, McGrath 31, Foley 30, Flynn 28, Morrissey 27, Kelly 26, Phelan 25, Sullivan 25, Whelan 23, McCarthy 22, Butler 21, Tobin 20.

Province of Ulster

Smith 134, Johnston 126, Stewart 126, Wilson 119, Thompson 101, O·Neill 98, Campbell 96, Moore 96, Bell 90, Robinson 89, Millar 86, Brown 82, Boyd 81, Scott 66, Graham 64, Reid 63, Martin 61, Kerr 60, Hamilton 50.

Murphy 50, Hughes 47, Wilson 45, Campbell 42, O·Hare 37, Smith 31, McCann 29, Donnelly 28, Watson 28, Quinn 26, Johnston 25, Kelly 25, Thompson 23.

Reilly 137, Smith 108, Brady 85, Lynch 51, McCabe 36, Clarke 30, Farrelly 29, Maguire 26, Sheridan 26, Galligan 20, Fitzpatrick 19, Dolan 18, McGovern 18, Donohoe 17, Martin 15, McMahon 15.

Doherty 80, McLaughlin 68, Kelly 50, Bradley 40, Brown 36, McCloskey 36, Campbell 33, Mullan 33, Smith 31, O·Neill 29, Kane 26, Moore 25, Gallagher 23.

Gallagher 196, Doherty 160, Boyle 102, O·Donnell 102, McLaughlin 81, Sweeney 50, Ward 40, Kelly 37, McGinley 37, McFadden 33, McGowan 33, Duffy 33, Campbell 28.

Thompson 55, Smith 53, Campbell 45, Patterson 41, Martin 35, Wilson 35, Graham 34, Johnston 34, Murray 33, Brown 31, Robinson 29, Hamilton 28, Bell 27, Scott 27, Boyd 25.

Maguire 44, McManus 30, Dolan 23, McGovern 23, Johnston 22, McHugh 20, Cassidy 17, Wilson 15, Thompson 14, Elliott 13, Irvine 13, McLoughlin 12, Gallagher 11, Murphy 11, Reilly 11, Fitzpatrick 10, Flanagan 10.

Duffy 38, Connolly 36, McMahon 33, McKenna 32, Hughes 25, Murphy 24, McCabe 22, Martin 19, Smith 19, Keily 18, Quinn 18, Maguire 17, Murphy 17, Woods 14.

Quinn 40, Mullan 39, Kelly 38, Donnelly 34, Gallagher 34, McKenna 33, Campbell 32, Hughes 31, Wilson 30, McLaughlin 29, O·Neill 29, Doherty 27, Smith 25, Hamilton 23.

Province of Connacht

Kelly 119, Burke 89, Conneely 89, Joyce 85, McDonagh 80, Walsh 80, Fahy 63, Mannion 59, Flaherty 48, Murphy 47, Connolly 46, Keane 40, King 36, Forde 35, Connor 33, Lyons 30, Mullin 30, Egan 29, Kenny 27, Toole 25.

Kelly 30, Reynolds 30, Flynn 20, McLoughlin 20, McHugh 19, Rooney 18, McMorrow 18, McTernan 17, Keany 16, McGowan 16, Moran 16, Reilly 16, Maguire 15, Dolan 14, Beirne 13, Gallagher 13, McDermott 13, McGovern 13, McShary 13, Mulvey 13.

Walsh 134, Gallagher 92, Kelly 89, Malley 78, Moran 77, Duffy 55, McHale 50, Gibbons 47, Joyce 46, Connor 45, Conway 40, Higgins 39, Murphy 39, Burke 36, Reilly 36, Durkan 35, Doherty 34, McHugh 34, Sweeney 33, Lyons 32.

Kelly 68, McDermott 45, Beirne 38, Regan 35, Flanagan 32, Connor 30, McDonagh 26, Quinn 25, Murray 24, Brennan 22, Higgins 22, Towey 22, Kenny 21, Flynn 20.

Brennan 31, McLoughlin 28, Gallagher 26, Kelly 23, Harte 20, McGowan 18, Walsh 18, Kennedy 16, Durkan 15, Henry 15, Flynn 14, Gilmartin 14, Leonard 14, Scanlon 14, Connolly 13, O·Hara 13, Feeney 11, Stenson 11, Conway 10, Sheridan 10.