Show ContentsO'Caseys History, Family Crest & Coats of Arms

In its ancient Gaelic form, the Irish name O'Caseys was written Ó Cathasaigh, from the word "cathasach," which means watchful. 1

Early Origins of the O'Caseys family

The surname O'Caseys was first found in the counties of Fermanagh, Mayo, Dublin, Limerick, Cork and Roscommon. In early times, there were six unrelated septs of Ó Cathasaigh; the two most important were the erenagh (church steward) families of Devenish in the county of Fermanagh and the Lords of the Suaithni, in the present-day barony of Balrothery West, in County Dublin. The name has since become widely scattered. Although it remains common in County Dublin, it is now most prevalent in the southwest of Munster, with a smaller but still sizable population in north Connacht. This corresponds with the locations of the other four septs, which were found at Liscannon near Bruff in the County Limerick; near Mitchelstown in County Cork; in Clondara in County Roscommon; and in Tirawley in County Mayo, where two Casey septs were located. The Caseys of Mayo and Roscommon, like those in Fermanagh, were also notable as erenaghs.

Archaeological remains indicate that Caseys were also once found near Waterford. Furthermore, a sept of MacCasey was once located at Oriel and was common in County Monaghan. However, this sept is nearly extinct today. Due to the widespread dropping of Irish prefixes under British rule and their often-erroneous resumption in the 20th century, many MacCaseys are incorrectly thought to be O'Caseys.

Early History of the O'Caseys family

This web page shows only a small excerpt of our O'Caseys research. Another 113 words (8 lines of text) covering the years 1172, 1381, 1551, 1723, 1762, 1765, 1773, 1787, 1800, 1801, 1840, 1846, 1848, 1862 and 1870 are included under the topic Early O'Caseys History in all our PDF Extended History products and printed products wherever possible.

O'Caseys Spelling Variations

During the Middle Ages, attempting to record a Gaelic name in English was a daunting task. Most names were spelt by scribes solely based on how it sounded, one's name could have been recorded many different ways during the life of its bearer. Numerous spelling variations were revealed in the search for the origin of the name O'Caseys family name.Variations found include Casey, MacCasey, O'Casey and others.

Early Notables of the O'Caseys family

Notable amongst the family name at this time was William Casey, Anglican bishop in Ireland, nominated Bishop of Limerick by King Edward VI on 6 July 1551 and consecrated at Dublin on 25 October 1551. Thomas Casey JP (1765-1840) was an Irish politician and barrister who was a Member of Parliament for Kilmallock in the Irish House of Commons from 1800...
Another 59 words (4 lines of text) are included under the topic Early O'Caseys Notables in all our PDF Extended History products and printed products wherever possible.

Migration of the O'Caseys family

Irish immigrants began to leave the English-controlled Ireland in sizable numbers during the late 18th century. Many of these Irish immigrated to British North America or the United States in the hopes of gaining their own tract of farmland. This pattern of migration grew steadily until the 1840s when the Great Potato Famine caused a great exodus of immigrants to North America. These immigrants differed from their predecessors in that they were desperately fleeing the disease and starvation that plagued their homeland, and many were entirely destitute when they arrived in North America. Although these penniless immigrants were not warmly welcomed when they arrived, they were critical to the rapid development of the United States and what would become known as Canada. Many went to populate the western frontiers and others provided the cheap labor the new manufacturing sector and the building of bridges, roads, railways, and canals required. A thorough examination of immigration and passenger lists has revealed some of the earliest people to arrive in North America with name O'Caseys or one of its variants: Elizabeth Casey who arrived in Maryland in 1725; as well as Andrew, Cornelius, Daniel, David, Edward, James, John, Mary, Michael, Patrick, Richard, Thomas and William Casey, who all arrived in Philadelphia between 1840 and 1865..



The O'Caseys 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: Per varios casus
Motto Translation: By various fortunes.


  1. MacLysaght, Edward, Supplement to Irish Families. Baltimore: Genealogical Book Company, 1964. Print.


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