Show ContentsCostilo History, Family Crest & Coats of Arms

The Costilo 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 Costilo, 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 Costilo family

The surname Costilo 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 Costilo family

This web page shows only a small excerpt of our Costilo 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 Costilo History in all our PDF Extended History products and printed products wherever possible.

Costilo Spelling Variations

During the Middle Ages, a single person often had their name recorded by church officials and scribes many different ways. Names were typically spelt as they sounded, which resulted in many different spelling variations. The many versions of the name Costilo to have been recorded over the years include: Costello, MacCostello, Costillo, Costallo, Kostello, McCostello, Caustello, Costellow and many more.

Early Notables of the Costilo 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 Costilo Notables in all our PDF Extended History products and printed products wherever possible.

Migration of the Costilo family

In the 1840s, Ireland experienced a mass exodus to North America due to the Great Potato Famine. These families wanted to escape from hunger and disease that was ravaging their homeland. With the promise of work, freedom and land overseas, the Irish looked upon British North America and the United States as a means of hope and prosperity. Those that survived the journey were able to achieve this through much hard work and perseverance. Early immigration and passenger lists revealed many bearing the name Costilo: 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 Costilo 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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