Show ContentsCastelow History, Family Crest & Coats of Arms

The Castelow 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 Castelow, 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 Castelow family

The surname Castelow 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 Castelow family

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

Castelow Spelling Variations

Church officials and medieval scribes spelled names as they sounded; therefore, single person, could have his name spelt many different ways during their lifetime. While investigating the origins of the name Castelow, many spelling variations were encountered, including: Costello, MacCostello, Costillo, Costallo, Kostello, McCostello, Caustello, Costellow and many more.

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


United States Castelow migration to the United States +

Ireland went through one of the most devastating periods in its history with the arrival of the Great Potato Famine of the 1840s. Many also lost their lives from typhus, fever and dysentery. And poverty was the general rule as tenant farmers were often evicted because they could not pay the high rents. Emigration to North America gave hundreds of families a chance at a life where work, freedom, and land ownership were all possible. For those who made the long journey, it meant hope and survival. The Irish emigration to British North America and the United States opened up the gates of industry, commerce, education and the arts. Early immigration and passenger lists have shown many Irish people bearing the name Castelow:

Castelow Settlers in United States in the 19th Century
  • James Castelow, who arrived in New York in 1837 3

Australia Castelow migration to Australia +

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

Castelow Settlers in Australia in the 19th Century
  • Joseph Castelow, English convict from York, who was transported aboard the "Agincourt" on July 6, 1844, settling in Van Diemen's Land, Australia 4

Contemporary Notables of the name Castelow (post 1700) +

  • Wilbur E. Castelow, American Democratic Party politician, Candidate for Connecticut State House of Representatives from Meriden, 1926 5


The Castelow 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. Filby, P. William, Meyer, Mary K., Passenger and immigration lists index : a guide to published arrival records of about 500,000 passengers who came to the United States and Canada in the seventeenth, eighteenth, and nineteenth centuries. 1982-1985 Cumulated Supplements in Four Volumes Detroit, Mich. : Gale Research Co., 1985, Print (ISBN 0-8103-1795-8)
  4. State Library of Queensland. (Retrieved 2014, November 24) Agincourt voyage to Van Diemen's Land, Australia in 1844 with 226 passengers. Retrieved from http://www.convictrecords.com.au/ships/agincourt/1844
  5. The Political Graveyard: Alphabetical Name Index. (Retrieved 2015, October 9) . Retrieved from http://politicalgraveyard.com/alpha/index.html


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