O'Callahan History, Family Crest & Coats of Arms
- Origins Available:
Before Irish names were translated into English, O'Callahan had a Gaelic form of O Ceallachain, possibly from "ceallach", which means "strife". The family is descended from Ceallachan (Callaghan), the 10th century King of Munster from whom their surname is derived, and as such, the name O'Callahan is a patronymic name.
Early Origins of the O'Callahan family
The surname O'Callahan was first found in Munster. The earliest mention of the name O'Callahan placed them in the barony of Kinlea, in County Cork, yet the family lost most of their original lands in the barony of Kinelea during the Anglo- Norman Conquest under Strongbow. They relocated to an area near Mallow, in the north of the county, and remained there until forced off their lands once again during the Cromwellian Invasion of the 17th century. The head family migrated to the east of County Clare and flourished, giving their name to the village of Callaghan's Mills. The resumption of the often-discarded prefix "O" has been widespread during the late twentieth century, but in the early twentieth century, Callaghans greatly outnumbered O'Callaghans, but such is no longer the case. The O'Callaghans are one of the few Irish families to still have a chief, certified by the Genealogical Office. 
Early History of the O'Callahan family
This web page shows only a small excerpt of our O'Callahan research. Another 202 words (14 lines of text) covering the years 1172, 1640, 1738, 1807, 1797, 1883, 1605, 1654, 1839 and 1909 are included under the topic Early O'Callahan History in all our PDF Extended History products and printed products wherever possible.
O'Callahan Spelling Variations
One's name was often recorded under several different spellings during the life of its bearer during the Middle Ages. Spelling variations revealed in the search for the origin of the O'Callahan family name include Callaghan, Callahan, O'Callaghan, O'Callahan, Calahan, Cellaghan, Kalahan, Kallaghan, Kallahan, O'Kallaghan, Kellaghan, Kelleghan, Kellahan, Kelahan, Ceilahan, Ceilaghan, Callachan, Calachan, Callagan, Calagan, Kelagan, Callighan and many more.
Early Notables of the O'Callahan family (pre 1700)
Another 35 words (2 lines of text) are included under the topic Early O'Callahan Notables in all our PDF Extended History products and printed products wherever possible.
Migration of the O'Callahan family
In the 18th and 19th centuries hundreds of thousands of Irish people immigrated to North American shores. The early settlers were enticed by the promise of their own land, but they were moderately well off in Ireland when they decided to emigrate. Therefore, they were merely carrying out a long and carefully thought out decision. The 1840s saw the emergence of a very different trend: thousands of extremely desperate people crammed into passenger boats hoping to find any type of opportunity. The Irish of this decade had seen their homeland severely stricken by crop failures which resulted in widespread disease and starvation. At whatever time the Irish immigrants came to North America, they were instrumental in the rapid development of the emerging nations of the United States and what would become known as Canada. An exhaustive search of passenger and immigration lists has revealed many persons bearing the name O'Callahan, or one of its variants: James Callaghan who settled in America in 1768; Gerhard Callaghan settled in 1764; James Callaghan settled in Pennsylvania in 1772; John Callaghan settled in Boston Massachusetts in 1764.
Contemporary Notables of the name O'Callahan (post 1700) +
- Joseph Timothy O'Callahan (1905-1964), American Jesuit priest
- John J. "Jack" O'Callahan (b. 1957), retired professional American ice hockey player
- Commander (Chaplain Corps) Joseph Timothy O'Callahan, American chaplain awarded the Congressional Medal of Honor in 1945
Related Stories +
- ^ MacLysaght, Edward, Irish Families Their Names, Arms and Origins 4th Edition. Dublin: Irish Academic, 1982. Print. (ISBN 0-7165-2364-7)