Show ContentsCostillowe History, Family Crest & Coats of Arms

The Costillowe surname came to Ireland with the Anglo-Norman invasion of the 12th century. They were originally from the Norman family Nangles, or de Angulos, and descended in Ireland from Gilbert de Nangle. Costello and associated variations come from the personal name of a son of Gilbert, Oisdealbhach, whose name consists of the elements "os," which means "deer or fawn", and "dealbhadh," which means "in the form of" or "resembling." The Gaelic form of the surname Costillowe, which predated the Anglicized version of the name, is Mac Oisdealbhaigh. This is the earliest recorded example of a Norman family assuming a Mac surname. The prefix O or Ó has sometimes been erroneously assumed. 1

Early Origins of the Costillowe family

The surname Costillowe was first found in County Mayo (Irish: Maigh Eo) located on the West coast of the Republic of Ireland in the province of Connacht, where they were granted lands by the Earl of Pembroke in the Anglo-Norman invasion of 1172.

Early History of the Costillowe family

This web page shows only a small excerpt of our Costillowe research. Another 138 words (10 lines of text) covering the years 1172, 1500, 1531, 1567, 1571, 1579, 1606, 1803 and 1865 are included under the topic Early Costillowe History in all our PDF Extended History products and printed products wherever possible.

Costillowe Spelling Variations

Church officials and medieval scribes often spelled early surnames as they sounded. This practice often resulted in many spelling variations of even a single name. Early versions of the name Costillowe included: Costello, MacCostello, Costillo, Costallo, Kostello, McCostello, Caustello, Costellow and many more.

Early Notables of the Costillowe family

Notable amongst the family up to this time was Guillauame Costeley (1531-1606), Scottish organist and 'valet du chambre du roy' to Henry II and Charles IX of France. 2 Arthur Dudley Costello (1803-1865), was an English-born Irish novelist and travel writer.William Costeley was a Scottish musician, born 1531, settled in France, and was organist to Henri II and Charles IX. Author of a treatise called...
Another 65 words (5 lines of text) are included under the topic Early Costillowe Notables in all our PDF Extended History products and printed products wherever possible.

Migration of the Costillowe family

In the mid-19th century, Ireland experienced one of the worst periods in its entire history. During this decade in order to ease the pressure of the soil, which was actually depleted by the effects of the previous years' grain crops, landowners forced tenant farmers and peasants onto tiny plots of land that barely provided the basic sustenance a family required. Conditions were worsened, though, by the population of the country, which was growing fast to roughly eight million. So when the Great Potato Famine of the mid-1840s hit, starvation and diseases decimated the population. Thousands of Irish families left the country for British North America and the United States. The new immigrants were often accommodated either in the opening western frontiers or as cheap unskilled labor in the established centers. In early passenger and immigration lists there are many immigrants bearing the name Costillowe: Honor Costello who landed in America in 1756; Bernard, Cornelius, Edward, Hugh, J.B. James, John, John B. Lawrence, Mark, Michael, Neal, Patrick, Peter, Philip, Thomas, Timothy, and William Costello, all landed in Philadelphia, Pennsylvania between 1833 and 1874.



The Costillowe Motto +

The motto was originally a war cry or slogan. Mottoes first began to be shown with arms in the 14th and 15th centuries, but were not in general use until the 17th century. Thus the oldest coats of arms generally do not include a motto. Mottoes seldom form part of the grant of arms: Under most heraldic authorities, a motto is an optional component of the coat of arms, and can be added to or changed at will; many families have chosen not to display a motto.

Motto: Ne te quaesiveris extra
Motto Translation: Seek nothing beyond your sphere.


  1. MacLysaght, Edward, The Surnames of Ireland. Ireland: Irish Academic Press, sixth edition, 1985. Print. (ISBN 0-7165-2366-3)
  2. Smith, George (ed), Dictionary of National Biography. London: Smith, Elder & Co., 1885-1900. Print


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