The disambiguation page Gallagher provides a list of people with this surname.

Gallagher is the anglicisation of the Irish

Irish language

Irish , also known as Irish Gaelic, is a Goidelic language of the Indo-European language family, originating in Ireland and historically spoken by the Irish people. Irish is now spoken as a first language by a minority of Irish people, as well as being a second language of a larger proportion of...

 surname Ó Gallchobhair (or a newer spelling form: Ó Gallchóir), these being masculine forms; the corresponding feminine forms are Ní Ghallchobhair (newer form Ní Ghallchóir). Apart from the aforementioned spelling there are at least 30 recorded variants including Gallacher, Gallager, Gallaher, Galliher, Gallaugher, Galagher, Galegher, and Goligher.

It is the most common surname in County Donegal

County Donegal

County Donegal is a county in Ireland. It is part of the Border Region and is also located in the province of Ulster. It is named after the town of Donegal. Donegal County Council is the local authority for the county...

 and the fourteenth most common by birth records in Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

. In the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, it was ranked by the 2000 U.S. Census as the 574th most common name out of over 80,000 surnames found. According to Professor

Professor

A professor is a scholarly teacher; the precise meaning of the term varies by country. Literally, professor derives from Latin as a "person who professes" being usually an expert in arts or sciences; a teacher of high rank...

 Edward MacLysaght

Edward MacLysaght

Edward MacLysaght was one of the foremost genealogists of twentieth century Ireland. His numerous books on Irish surnames built upon the work of Patrick Woulfe's Irish Names and Surnames and made him well known to all those researching their family past.-Early life:Edward was born in Flax Bourton...

, in the mid 20th century Gallagher was one of the most common Irish surnames, most of the recorded births being located in the north-west provinces of Ulster

Ulster

Ulster is one of the four provinces of Ireland, located in the north of the island. In ancient Ireland, it was one of the fifths ruled by a "king of over-kings" . Following the Norman invasion of Ireland, the ancient kingdoms were shired into a number of counties for administrative and judicial...

 and Connacht

Connacht

Connacht , formerly anglicised as Connaught, is one of the Provinces of Ireland situated in the west of Ireland. In Ancient Ireland, it was one of the fifths ruled by a "king of over-kings" . Following the Norman invasion of Ireland, the ancient kingdoms were shired into a number of counties for...

, with the majority being recorded in the homeland of the sept

Sept

A sept is an English word for a division of a family, especially a division of a clan. The word might have its origin from Latin saeptum "enclosure, fold", or it can be an alteration of sect.The term is found in both Ireland and Scotland...

 - Co Donegal.

Ó Gallchobhair sept

The Ó Gallchobhair sept

Sept (social)

A sept is an English word for a division of a family, especially a division of a clan. The word might have its origin from Latin saeptum "enclosure, fold", or it can be an alteration of sect.The term is found in both Ireland and Scotland...

 claims to be the most senior family of the Cenél Conaill

Cenél Conaill

The Cenél Conaill is the name of the "kindred" or descendants of Conall Gulban, son of Niall Noígiallach defined by oral and recorded history. They were also known in Scotland as the Kindred of Saint Columba....

. The sept's territory was spread across the areas within the modern baronies of Raphoe

Raphoe

Raphoe is a town in County Donegal, part of the province of Ulster in Ireland. It is the main town in the fertile district of East Donegal known as the Laggan, as well as giving its name to the Roman Catholic Diocese of Raphoe and the Church of Ireland Diocese of Derry and Raphoe.-Name:Raphoe,...

 and Tirhugh in Co Donegal. From the 14th century until the 16th century, the sept's chiefs were marshals in the O'Donnells' military forces. The principal branch of the family was centred at Ballybeit and Ballynaglack.

Gallagher Ecclesiastics in the 16th Century

Redmond O'Gallagher was appointed Bishop of Killala

Bishop of Killala

The Bishop of Killala is an episcopal title which takes its name after the town of Killala in County Mayo, Ireland. In the Roman Catholic Church it remains a separate title, but in the Church of Ireland it has been united with other bishoprics.-History:...

 by Pope Paul III

Pope Paul III

Pope Paul III , born Alessandro Farnese, was Pope of the Roman Catholic Church from 1534 to his death in 1549. He came to the papal throne in an era following the sack of Rome in 1527 and rife with uncertainties in the Catholic Church following the Protestant Reformation...

 in 1545 and presumably was recognized by the Crown in the reign of Queen Mary I

Mary I of England

Mary I was queen regnant of England and Ireland from July 1553 until her death.She was the only surviving child born of the ill-fated marriage of Henry VIII and his first wife Catherine of Aragon. Her younger half-brother, Edward VI, succeeded Henry in 1547...

, but there is no record of his recognition by Queen Elizabeth I

Elizabeth I of England

Elizabeth I was queen regnant of England and Ireland from 17 November 1558 until her death. Sometimes called The Virgin Queen, Gloriana, or Good Queen Bess, Elizabeth was the fifth and last monarch of the Tudor dynasty...

. In 1569, Redmond O'Gallagher was appointed Bishop of Derry

Bishop of Derry

The Bishop of Derry is an episcopal title which takes its name after the city of Derry in Northern Ireland. In the Roman Catholic Church it remains a separate title, but in the Church of Ireland it has been united with another bishopric.-History:...

. He died in office on the 15 March 1601.

Donat O'Gallagher, O.F.M. succeeded Redmond as Bishop of Killala

Bishop of Killala

The Bishop of Killala is an episcopal title which takes its name after the town of Killala in County Mayo, Ireland. In the Roman Catholic Church it remains a separate title, but in the Church of Ireland it has been united with other bishoprics.-History:...

 in 1570. In 1580, Donat was appointed Bishop of Down and Connor

Bishop of Down and Connor

The Bishop of Down and Connor is an episcopal title which takes its name from the town of Downpatrick and the village of Connor in Northern Ireland...

 and died in office in 1581.

17th Century and the Flight of Earls

In the Annals of the Four Masters

Annals of the Four Masters

The Annals of the Kingdom of Ireland or the Annals of the Four Masters are a chronicle of medieval Irish history...

, on 14 September 1607, mention by Tadhg Ó Cianáin

Tadhg Ó Cianáin

Tadhg Og Ó Cianáin was an Irish writer.He was the author of Imeacht na nIarlaí/The Earls' Departure, a diary of the Flight of the Earls, kept from September 1607 to November 1608, from Rathmullen, County Donegal to Rome. It is the earliest example in Irish of the diary genre...

 is made of five Gallaghers named Cathaoir (mac Toimlin), Cathaoir (mac Airt), Toirleach Corrach, Tuathal and Aodh Og who fled Ireland with the O'Donnells. They stayed in Belgium

Belgium

Belgium , officially the Kingdom of Belgium, is a federal state in Western Europe. It is a founding member of the European Union and hosts the EU's headquarters, and those of several other major international organisations such as NATO.Belgium is also a member of, or affiliated to, many...

 and joined the O'Neill regiment

Owen Roe O'Neill

Eoghan Ruadh Ó Néill , anglicised as Owen Roe O'Neill , was a seventeenth century soldier and one of the most famous of the O'Neill dynasty of Ulster.- In Spanish service :...

 in the Spanish Army of Flanders

Army of Flanders

The Army of Flanders was a Spanish Habsburg army based in the Netherlands during the 16th to 18th centuries. It was notable for being the longest standing army of the period, being in continuous service from 1567 until its disestablishment in 1706...

. The regiment fought against the Dutch during the Eighty Years' War. Aodh Ó Gallchobhair and his wife (mentor and nursemaid of O'Donnell sons) chose to travel with the O'Donnells to Rome

Rome

Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...

.

Arms

The Gallagher coat of arms

Coat of arms

A coat of arms is a unique heraldic design on a shield or escutcheon or on a surcoat or tabard used to cover and protect armour and to identify the wearer. Thus the term is often stated as "coat-armour", because it was anciently displayed on the front of a coat of cloth...

 displays a black lion rampant on a silver shield, treading on a green snake surrounded by eight green trefoil

Trefoil

Trefoil is a graphic form composed of the outline of three overlapping rings used in architecture and Christian symbolism...

s. The correct heraldic description is "Field argent a lion rampant sable treading on a serpent in fess proper between eight trefoils vert". The crest

Crest (heraldry)

A crest is a component of an heraldic display, so called because it stands on top of a helmet, as the crest of a jay stands on the bird's head....

 which surmounts the helmet

Helmet

A helmet is a form of protective gear worn on the head to protect it from injuries.Ceremonial or symbolic helmets without protective function are sometimes used. The oldest known use of helmets was by Assyrian soldiers in 900BC, who wore thick leather or bronze helmets to protect the head from...

 over the shield depicts a red crescent

Crescent

In art and symbolism, a crescent is generally the shape produced when a circular disk has a segment of another circle removed from its edge, so that what remains is a shape enclosed by two circular arcs of different diameters which intersect at two points .In astronomy, a crescent...

 surrounding a green snake or, to give its heraldic definition, "A crescent gules out of the horns a serpent erect proper". The motto

Motto

A motto is a phrase meant to formally summarize the general motivation or intention of a social group or organization. A motto may be in any language, but Latin is the most used. The local language is usual in the mottoes of governments...

 of the clan

Clan

A clan is a group of people united by actual or perceived kinship and descent. Even if lineage details are unknown, clan members may be organized around a founding member or apical ancestor. The kinship-based bonds may be symbolical, whereby the clan shares a "stipulated" common ancestor that is a...

 is in Latin

Latin

Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...

 Mea Gloria Fides ("The Faith is My Glory").

Origins

The clan

Clan

A clan is a group of people united by actual or perceived kinship and descent. Even if lineage details are unknown, clan members may be organized around a founding member or apical ancestor. The kinship-based bonds may be symbolical, whereby the clan shares a "stipulated" common ancestor that is a...

 hails from the barony of Tirhugh ("land of Hugh") near Ballyshannon

Ballyshannon

Ballyshannon is a town in County Donegal, Ireland. It is located where the N3 and N15 cross the River Erne, and claims to be the oldest town in Ireland.-Location:...

, County Donegal

County Donegal

County Donegal is a county in Ireland. It is part of the Border Region and is also located in the province of Ulster. It is named after the town of Donegal. Donegal County Council is the local authority for the county...

, Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

.

The derivation of the surname Gallagher is "foreign help" or "foreign helper" from the Irish

Irish language

Irish , also known as Irish Gaelic, is a Goidelic language of the Indo-European language family, originating in Ireland and historically spoken by the Irish people. Irish is now spoken as a first language by a minority of Irish people, as well as being a second language of a larger proportion of...

 gall meaning "stranger" and cobhair meaning "help". It is a matter of conjecture whether this appellation denoted merely an ally of strangers from other parts or, as has been suggested, more particularly a collaborator with the Norsemen

Norsemen

Norsemen is used to refer to the group of people as a whole who spoke what is now called the Old Norse language belonging to the North Germanic branch of Indo-European languages, especially Norwegian, Icelandic, Faroese, Swedish and Danish in their earlier forms.The meaning of Norseman was "people...

, who were in those days raiding the coast of north west Ireland. The family's origins are with the chieftain

Chieftain

Chieftain may refer to:The leader or head of a group:* a tribal chief or a village head.* a member of the 'House of chiefs'.* a captain, to which 'chieftain' is etymologically related.* Clan chief, the head of a Scottish clan....

 Aodh, a name corresponding to the English Hugh (whence Tirhugh), a lineal descendant of Conall Gulban

Conall Gulban

Conall Gulban was an Irish king who founded the kingdom of Tír Conaill in the 5th century, comprising much of what is now County Donegal. He was the son of Niall Noígiallach....

 son of 5th century High King

High king

A high king is a king who holds a position of seniority over a group of other kings, without the title of Emperor; compare King of Kings.Rulers who have been termed "high king" include:...

 and warlord

Warlord

A warlord is a person with power who has both military and civil control over a subnational area due to armed forces loyal to the warlord and not to a central authority. The term can also mean one who espouses the ideal that war is necessary, and has the means and authority to engage in war...

 Niall Noígíallach, known in English as Niall of the Nine Hostages, who is reputed to have brought St Patrick to Ireland as a slave. Aodh established his dunarus or residence at a place corresponding to the present day townland

Townland

A townland or bally is a small geographical division of land used in Ireland. The townland system is of Gaelic origin—most townlands are believed to pre-date the Norman invasion and most have names derived from the Irish language...

 of Glassbolie in Tirhugh. The chieftains of his line ruled in relative peace for several generations until the arrival of the Vikings in Donegal Bay

Donegal Bay

Donegal Bay is an inlet in the northwest of Ireland. Three counties – Donegal to the north and west, Leitrim and Sligo to the south – have shorelines on the bay, which is bounded on the west by the Atlantic Ocean...

in the 9th century. The ruling chieftain of the time, whose real name is not recorded, was almost certainly obliged to come to some accommodation with the foreign invader resulting in the nickname "Gallcóbhair" which has been applied to his descendants thereafter.