Select Dempsey Surname Genealogy

Dempsey is an anglicized version of O'Dempsey, the ancestor of O'Diomsaigh.  This family name came from the Gaelic word diomusach, meaning "proud" or "haughty."  The O'Diomsaighs originated in the territory known as Clanmalier, on the borders of what are now the Laois and Offaly counties in Ireland. 

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Ireland.  The Annals of the Four Masters recorded in 1193 the death of Dermot O'Dempsey, son of Cubgogda.  He was Chief of Clanmalier, for a long time Lord of Offaly, and the founder of the Cistercian abbey at Monasterevan in county Kildare.  He also led the Leinster resistance against the Anglo-Norman invasion in the 1170's under Strongbow and defeated him in battle.

The O'Dempsey territory, known as Clann Mhaoilughra, comprised a vast area on both sides of the Barrow river and included the baronies of Philipstown in Offaly, Portnahinch in Laios, and West Offaly in Kildare.  Lea Castle in Portnahinch, often occupied by the O'Dempseys, lay in the center of these lands.  Successive O'Dempsey clan chiefs held onto their territory. 

In the 16th century, the O'Dempseys were on friendly terms with the English, fighting with them in their attacks on the Irish clans at Mullamast in 1577, and their estates escaped confiscation.  Terence O'Dempsey was knighted in 1599 and created Viscount Clanmalier in 1631.

The O'Dempseys then switched sides.  Three of their number were prominent members of the Confederation of Kilkenny during Cromwellian times.  Loyalty to the Catholic King James II then resulted in the forfeiture of all their lands in 1691.  O'Dempseys had been prominent in the Battle of the Boyne.  Many O'Dempseys were evicted from their homes and driven into neighboring counties such as Tipperary.  As one English commentator noted:

"Viscount Clanmalier was head of this family at the Revolution of 1688.  They are now obscure and sunk into poverty and degradation."

This clan history has most recently been recorded in Patrick Goode's 2008 book The O'Dempsey Chronicles.
The Dempsey name is still strong in Laois and Offaly, particularly in their own homeland, but it has also spread throughout Ireland.   It is quite common in county Antrim in Ulster where it may be an Irish version of the Scottish name Dempster.  There were a number of Presbyterian farming families called Dempsey in the parishes of north Antrim in the 19th century.

  After the confiscation of the Clanmalier lands in 1691, Terence O'Dempsey left Ireland and settled in Cheshire.  A descendant of this line was General Sir Miles Dempsey, a commander of the British Second Army during the D-Day landings in 1944.

James and Ann Dempsey were married in Liverpool in 1821 and James was a timber merchant.

"The anecdotal account was that the Dempsey family emanated from Ireland and that the daughters of James and Ann were known as 'the Dempsey beauties.'"

These Dempseys were part of a close-knit coterie of Liverpool merchant families which often intermarried. Daughter Ann Dempsey married the shipowner Thomas Holderness, daughter Frances the merchant William Tarbet, daughter Louisa the Liverpool MP John Torr, and daughter Maria the banker John Smith.

Many Dempseys came from Ireland to industrial Lancashire in the second half of the 19th century, in search of jobs.

America.  The earliest Dempsey arrival in America was probably William Dempsey who came to Philadelphia in 1726 as a young boy and made his home in Virginia.  Barnet Dempsey from county Kildare came to Spartanburg, South Carolina sometime in the 1780's.  His son Levi moved onto Georgia. 

Captain Michael Dempsey, who emigrated to America in the 1830's, was from Lea parish in Laois and believed to be related to the Dempseys of Clanmalier.  He enlisted in the US Army, fought in Florida in the Seminole Indian War, and ended up farming in Catahoula parish, Louisiana.

More Dempseys arrived later in the 19th century via ports in the northeast.  Among them were:
  • Michael Dempsey and his sisters from Dublin onboard the Mount Washington to Boston in 1849.  They settled in the Boston area.
  • Lawrence Dempsey from Wexford onboard the Monongahela to Philadelphia in 1850.  Lawrence later married and they moved to Lee county, Illinois to farm.  A Dempsey still lives on part of their farm today.
John Dempsey arrived with his family from Tipperary in 1925.  He rose through the political ranks to be Governor of Connecticut from 1961 to 1970.

There were two famous Jack Dempseys in America who were world boxing champions:
  • the first Jack Dempsey, known the Jack Dempsey the non pareil, came from Ireland but spent most of his boxing life in America.  Sadly, he died young of TB. 
  • the second, known as the Manassa Mauler, was born in Colorado from a family that had hailed originally from West Virginia.  He lived on after retirement to run Jack Dempsey's Restaurant in New York.  
Australia.  James Dempsey, a United Irishman, had been part of the Vinegar Hill rebellion in Wexford in 1798, resulting in his transportation to Australia.  He was granted his freedom in 1809 and his home became a spiritual and communial center for the sizeable disenfranchised Irish Catholic population of Sydney.  He devoted his time, money, and effort in later life to the building of the first Catholic chapel in Australia for this community.

Among the later free settlers to Australia were:
  • Thomas O'Dempsey and his family on the Ballarat from Wexford in 1828.  They arrived in Melbourne.
  • Newly-weds James and Johanna Dempsey from Tipperary in 1855.  They came to Queensland and were one of the early settlers in Upper Freestone.
Select Dempsey Miscellany

If you would like to read more, click on the miscellany page for further stories and accounts:

Select Dempsey Names

Dermot O'Dempsey, who died in 1193, was the first leader of the O'Dempsey clan.  He led the Leinster resistence to the Anglo-Norman invasion under Strongbow.
James Dempsey built the first Roman Catholic chapel in Australia.
Jack Dempsey (born John Kelly) was an Irish-born boxer called the "nonprareil" becsuse no one could beat him.  He died in 1895 at the tender age of 33. 
Jack Dempsey, known as the "Manassa Mauler," was world heavyweight champion from 1919 to 1926.

Select Dempseys Today
  • 8,000 in the UK (most numerous in London)
  • 10,000 in America (most numerous in New York)
  • 16,000 elsewhere (most numerous in Ireland).

PS.  You might want to check out the surnames page on this website.  It covers surname genealogy in this and companion websites for more than 800 surnames.

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