Cassidy History

"The Cassidys in early years were the doctors to the Maguires, very proud name.  A Cassidy is a great name, the name gets a welcome anywhere."
Pat Cassidy, Rest in Peace

LoughErne in Co. Fermanagh where Cassidys originated.


An Ancient Irish Name

        Cassidy - Cassidy - Caiside is an ancient Irish name.  In the United States, many Cassidy variations exist, including Cassity, Cassedy and Casada. 

        All Cassidys originate from County Fermanagh, Northern Ireland, where for centuries they were prominent in the arts and fields of medicine and religion.  Like other professional families, over time they moved out to other parts of Ulster province and all of Ireland. 

        The origin of Ui Caiside, the Cassidys, remains unknown.  There is a dispute as to whether they belonged to the Fir Manaigh, the first Celtic settlers of County Fermanagh, or migrated to the area in the sixth century A.D. during the time of St. Molaise who founded the monastery at Devenish Island.  Ui Caiside was closely linked to the monastery and had access to its school at a time when education was denied to most. 

         In his analysis of the family, Father P.O. Gallachair, a historian of the region, states, "Soon the Ui Caiside name was renowned, but unlike most ancient Irish families their fame was never won in mere physical feats of arms, in blood and tears.  Theirs was a higher, more noble fame.  They were men of peace, culture and scholarship."


In 1995, President Clinton visited Cassidy's Pub in Dublin.

The Ballycassidy, Co. Fermanagh, post office.


Heritage as Physicians

        From the very earliest times the Irish physician was attached to the clan or house of a chieftain, and the profession of the physician passed from father to son just as did the profession of the other arts and crafts in the country.  While this hereditary character of medical practice existed in other countries, in Ireland, it persisted until comparatively recent times.  Thus, there were the Cassidys of Fermanagh, the Callenans of Desmond, the Lees of Connaught among the leading Irish medical families.

        The Ui Caiside served as hereditary physicians to the Mac Uidhir (Maguire of Fermanagh), the chieftains of Fermanagh.  Cassidys are recorded as physicians to the Maguires between 1300 and 1600, and were also found practicing in the midlands of Ireland.  For example, the Annals of the Four Masters notes the death in 1504 of Pierce Cassidy of Coole in Fermanagh, "the son of Thomas, chief physician to Maguire, a man profoundly versed in literature and medicine, and who kept a house of general hospitality." Other principal Ui Caside physicians were Finghin (d. 1322); Gilla na nAingel (d. 1335); Tadhg (d. 1450); Feonis (d. 1504) and Feidhlimidh (d. 1520). All are mentioned in the Annals of Ireland as ollamh leighis or professors of medicine.

        The death of Feoris is recorded somewhat fully in the Annals of Ulster:  "O'Cassidy of Ceul died this year-that is Maguire's Ollave physician and a well tried doctor in learning and physic in theory and in practise and a man who kept a house of general hospitality for every one and he died of Cruith an Righ."  This latter was a sickness of unknown identity which is mentioned several times in the Annals as occurring in epidemics. The name (King's Game in English) may arise from the belief that, like the King's Evil, it was curable by a royal touch.

        Although the hereditary nature of the profession created pressure for medieval Irish physicians to reside close to their patron chieftain, Irish physicians traveled extensively.  In the 14th and 15th centuries, many went to continental Europe for training and brought back medical texts used centuries later.  They also frequently traveled around Ireland to exercise their skills and extend their knowledge. 

        In the 16th century it was more typical for Irish doctors to study in schools established in Ireland or Scotland.  Often each medical family compiled, and handed down to succeeding generations, medical manuscripts for their own use and for fellow doctors.  From this period, Cassidys are identified as the authors of many medical tracts.  One manuscript, written by An Giolla Glas Caiside between 1515 and 1527, still exists and is in the library of Corpus Christi College, Oxford.  It contains scientific commentary on a wide range of topics including medicine, philosophy, astronomy and botany.   Later famous Cassidy physicians include Dr. Felix Cassidy, who served in the Jacobite Court in France.   

        See also Cassidys Today for a profile of Dr. Sheila Cassidy.

Heritage as Priests and Scholars

        Cassidys were noted as "a most prominent, and is some ways a unique house, a people apart."   This acclaim stemmed in part from their long history as priests and scholars in the Diocese of Clogher, especially during the suppression of the Roman Catholic Church under the Penal Laws of the 18th Century.  As explained on the Irish terminology page, Catholic church divisions did not conform to county boundaries.  The Diocese of Clogher contains most of County Fermanagh, all of Monaghan, parts of Donegal, Tyrone, and a small piece of Louth.

        The most important early Irish Cassidy priest and scholar was Ruaidhri Caiside (Rory Cassidy, died 1541), the archdeacon of Clogher.  In 1525, Caiside compiled the "Register of the Diocese of Clogher."  He also carried on the work of Cathal g MacManus, who died in 1498, in the compilation of the "Annals of Ulster." 

        The Annals are one of the most significant Irish texts from the later middle ages, containing a reliable record of events of local and national significance along with information on family relationships, men of learning, and social development.  In the entry for 1541, it reads, "Rory Cassidy, this is the Archdeacon of Clogher, died this year.  And it is he who wrote the greater part of this book [the "B" copy of the annals], a man who was full of knowledge in every science, both law and divinity, medicine and philosophy, to the time of his death."

        Less noteworthy, but certainly colorful (and possibly bearing traits found within a Cassidy you might know today), was Maurice Cassidy, a Franciscan born in 1745.  A contemporary claimed he was "a boisterous, fire eating Ulsterman who was not above using fisticuffs to emphasize his commands, and who was left in office only one year."


Cassidy Graves on Devenish Island, including grave of Cassidy priests from the 17-18th centuries on the left and center.  See two enlargements of the grave of Cassidy priests.



           The contribution of the Cassidys to the priesthood originated from their position as one of the hereditary "church families" in County Fermanagh.  Prior to 1600, large parts of Ireland, including one-sixth of the county in the Maguire period, were owned by the church.   Local families, however, possessed the estates surrounding the churches and monasteries.  The chief of the family bore the title of "erenagh."  A single church with extensive lands might have several erenaghs, each erenagh controlling a separate part of the church's lands.

        The inhabitants of the church lands were accorded many of the privileges of the clergy, such as immunity from secular taxation, neutrality in time of war, and freedom from military service.  With the transformation of the Irish church in 12th century from a monastic church to one based on a diocesan and parochial system, these lands vested in the local bishops. 

        In return for continuing possession of the lands, the erenaghs paid the bishop an annual rent, many specific tributes and services, including a night's lodging and entertainment for the bishop and his train, helped maintain the local church and were obligated to maintain hospitality for "pilgrams, strangers and poor travelers."  The members of erenagh families enjoyed a quasi-clerical status, and a greater part of the clergy was recruited from these families. 

        For a profile of Cardinal Edward Cassidy, arguably the most prominent Roman Catholic Cassidy priest in history, see Cassidys Today.

Heritage as Poets

        The earliest renowned Cassidy poet was Giolla Mochuda Mor Caiside (also identified as Gilla Mo Dutu ua Casaide).  Before the Maguires assumed control of Fermanagh, Caiside was famed among the lir lighinn, the men of learning of Ireland "for all that was superior in Gaelic literature."   Caiside wrote in 1147 the poem Banshenchas (The Lore of Woman), which tells the history of women of the world. 


Map showing influence of learned families in southeast Ulster, including County Fermanagh.

        Still widely read and sung is the poetry of Tomas Cassidy, "An Caisideach Ban" or the fair-haired Cassidy.   Cassidy was an 18th Century Augustian friar expelled from the friary, in his own words, "on account of a bad senseless marriage."  He spent the rest of life wandering across Ireland and Europe as a poet and renegade priest.    Cassidy's most famous poem is An Caisideach Ban, which, as stated on one Irish album, is "sung the length and breath of Ireland.  It is the story of Cassidy, a priest, who lusts after a fair maiden and his final wish on his death bed would be to get a kiss from her."  

        For more commentary on the Cassidy heritage as poets, see Irish Poetry & The Cassidy Contribution.

Cassidy-Clinton Connection

        Former President Bill Clinton is a Cassidy, as his mother's maiden name was Virginia Dell Cassidy.  President Clinton has Irish ancestry from both parents.  His Cassidy roots in America date back five generations to Levi Cassidy (c1790-c1850) of Chesterfield, South Carolina.

        President Clinton, whose father died before he was born, lived with his maternal grandparents for several years as a childe while his mother attended nursing school.  President Clinton credits his grandfather, James Eldridge Cassidy, with instilling in him a love for  learning and teaching him to read by age four.  

        On his 1995 visit to Ireland, former President Clinton in a speech at College Green in Dublin observed, "My mother was a Cassidy and how I wish she were alive to be here with me today.  She would have loved the small towns and she would have loved Dublin.  Most of all, she would have loved the fact that in Ireland, you have nearly 300 racing days a year.  She loved the horses."

        On December 12, 2000, during his final visit to Ireland as President, he observed, "When I started come here, you know, I got a lot of help in rooting out my Irish ancestry.  And the oldest known homestead of my mother's family, the Cassidys, that we've been able to find is a sort of mid 18th century farmhouse that's in Rosleigh and Fermanagh.  But it's right on the - literally right on the border.  And in my family, all the Catholics and Protestants intermarried, so maybe I was somehow genetically prepared for the work I had to do.   Maybe it's because there are 45 million Irish Americans, and I was trying to make a few votes at home.  The truth is, it just seemed to me the right thing to do."


For profiles of prominent Cassidys, see Cassidys Today.

The Surname Caiside provides an explanation on the origin of Cassidy surname by a leading professor on the Irish language. 

Ever wonder why there are so variations of Cassidy in the United States?   See the discussion at Cassidy Variations.


The Cassidy Clan is pleased to announce the release of the book "Speculated Truth: A Genealogical Journey of Truth and Speculation" by Clan Secretary Brent Cassidy. The book is for all persons interested in Cassidy genealogy, Irish culture, traveling to County Fermanagh and Ireland.  Please click here to read more about the book and learn how to order a copy.

Inch Strand in County Kerry on the Dingle Peninsula by Sarah Cassidy.
Click here to view a larger image