Show ContentsDemsy History, Family Crest & Coats of Arms

Today's Irish surnames are underpinned by a multitude of rich histories. The name Demsy originally appeared in Gaelic as Ó Diomasaigh, from the word "diomasach," which means "proud." 1

Early Origins of the Demsy family

The surname Demsy was first found in King's County and Queen's County, where they were traditional Chiefs of Clanmaliere, a territory that lay on both sides of the river Barrow. It contained parts of Geashill and Phillipstown in Kings County and parts of Portnehinch in Queen's County. They claim descent through the O'Connors of Offaly, specifically the 2nd century Irish King, Cathair Mor. 2

According to O'Hart, they claim descent from through the "Connor" Faley pedigree.

Early History of the Demsy family

This web page shows only a small excerpt of our Demsy research. Another 286 words (20 lines of text) covering the years 1172, 1193, 1599, 1631, 1641, 1652 and 1865 are included under the topic Early Demsy History in all our PDF Extended History products and printed products wherever possible.

Demsy Spelling Variations

Within the archives researched, many different spelling variations of the surname Demsy were found. These included One reason for the many variations is that scribes and church officials often spelled an individual's name as it sounded. This imprecise method often led to many versions. Dempsey, O'Dempsey, Dempsy, Dempsay, Dempsie and many more.

Early Notables of the Demsy family

Notable among the family name at this time was Sir Terence O'Dempsey, knighted May 1599, by Robert Devereux, earl of Essex, Lord Lieutenant of Ireland. Terence was created "Baron of Philipstown," and Viscount Clanmaliere, by patent dated 8th July, 1631, temp. Charles I. He had five sons, two of which were clergy:...
Another 52 words (4 lines of text) are included under the topic Early Demsy Notables in all our PDF Extended History products and printed products wherever possible.

Migration of the Demsy family

During the 19th century thousands of impoverished Irish families made the long journey to British North America and the United States. These people were leaving a land that had become beset with poverty, lack of opportunity, and hunger. In North America, they hoped to find land, work, and political and religious freedoms. Although the majority of the immigrants that survived the long sea passage did make these discoveries, it was not without much perseverance and hard work: by the mid-19th century land suitable for agriculture was short supply, especially in British North America, in the east; the work available was generally low paying and physically taxing construction or factory work; and the English stereotypes concerning the Irish, although less frequent and vehement, were, nevertheless, present in the land of freedom, liberty, and equality for all men. The largest influx of Irish settlers occurred with Great Potato Famine during the late 1840s. Research into passenger and immigration lists has brought forth evidence of the early members of the Demsy family in North America: Ann, Biddy, Bridget, Catherine, John, and Henry Dempsey who settled in Quebec in 1840; Edward Dempsey settled in New York in 1810; Jeremiah Dempsey settled in Mississippi in 1820.



  1. MacLysaght, Edward, Irish Families Their Names, Arms and Origins 4th Edition. Dublin: Irish Academic, 1982. Print. (ISBN 0-7165-2364-7)
  2. O'Hart, John, Irish Pedigrees 5th Edition in 2 Volumes. Baltimore: Genealogical Publishing Company, 1976. Print. (ISBN 0-8063-0737-4)


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