Show ContentsCostelow History, Family Crest & Coats of Arms

The Costelow 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 Costelow, 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 Costelow family

The surname Costelow 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 Costelow family

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

Costelow Spelling Variations

Since church officials and medieval scribes spelt each name as it sounded to them; as a result, a single person could accumulate many different versions of his name within official records. A close examination of the origins of the name Costelow revealed the following spelling variations: Costello, MacCostello, Costillo, Costallo, Kostello, McCostello, Caustello, Costellow and many more.

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


Australia Costelow migration to Australia +

Emigration to Australia followed the First Fleets of convicts, tradespeople and early settlers. Early immigrants include:

Costelow Settlers in Australia in the 19th Century
  • William Costelow, who arrived in Adelaide, Australia aboard the ship "Susannah" in 1849 3


The Costelow 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
  3. State Records of South Australia. (Retrieved 2010, November 5) SUSANNAH 1849. Retrieved from http://www.slsa.sa.gov.au/BSA/1849Susannah.htm


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