geography
Two McManus Septs
The McManus name is associated with two principal Irish septs: one connected with the O’Conors of Roscommon, the other with the Maguires of Fermanagh. A sept is a family or kinship branch associated with a wider lineage and territory.
These traditions provide historical context for surname research. They do not, by themselves, establish which medieval family a present-day McManus descends from.
Roscommon: the O’Conor connection
Maghnus and the family tradition
The Roscommon tradition traces the family to Maghnus, who died in 1181, a son of Turlough Mór O’Conor, High King of Ireland. The genealogy cited in the earlier account names him as Maghnus Miogharan and identifies him as Turlough’s ninth son, referring to The Book of Lecan, folio 72, b, column 4.
Tír Tuathail and Kilronan
The family was associated with Tír Tuathail, in the northeastern part of the Barony of Boyle in North Roscommon, around the area of Kilronan.
The older account connects the territorial name with Tír Tuathail Maoilgairbh, “the country of Tuathal Maelgarbh,” citing O’Flaherty’s Ogygia, part 3, chapter 93.
The MacDermotts of Moylurg
The territory later came under the authority of the MacDermotts of Moylurg. The account cited as Southeran (1871, p. 73) discusses the limits of the surviving McManus pedigree and the subsequent possession of the land by MacDermot Roe under MacDermot of Moylurg.
Explore the Roscommon collection.
Fermanagh: the Maguire connection
Maghnus Maguire
The Fermanagh tradition identifies the McManuses as a branch of the Maguire family, tracing their ancestry to Maghnus Maguire, associated in the earlier account with Donn Mag Uidhir, chief of Fermanagh. That account places the emergence of the McManus name in this branch in the fourteenth century.
The precise genealogy and dates should be tied to individual source entries before being used to establish a family’s descent.
Ballymacmanus and Belle Isle
The family’s seat is associated with Seanadh Mhic Mhaghnusa, also described as Baile Mhic Mhaghnusa, in Lough Erne. The island appears in the older account as Ballymacmanus, later known as Belle Isle, between the baronies of Magherastephana and Clanawley.
Landholding and dispossession
The account cited as Southeran (1871, p. 85) describes the loss of MacManus and Maguire estates in strongly critical terms:
Nearly all the magnificent possessions of the MacManuses and Maguires were, it is well known most shamefully confiscated by the English government; as to their rightful proprietors, they, their numerous dependents and other native Irish inhabitants, were, as I have before stated, mercilessly driven out to beggary and starvation.
A comment attributed in the earlier article to Phillip McManus of the McManus Clan Association offers a more varied picture:
Not all McManuses were made beggarly by the dispossession of Ballymacmanus. We kept the fisheries, the property on Knockninny, etc.
He also described his branch’s landholdings in County Antrim and suggested that political alliances may have helped it retain property. That family account is a useful research lead; the relevant deeds and land records would help establish the details.
Explore the Fermanagh collection.
DNA and the research question
DNA research may help distinguish paternal branches sharing the McManus surname and identify lines worth investigating together. A shared surname or DNA connection alone does not prove descent from either medieval sept.
The research question is how genetic connections fit with documented relationships, places, dates, and surviving records.
Explore the site’s Y-DNA research.
Sources and further reading
The historical references below are retained from the earlier article. They are research pointers rather than a newly verified pedigree; full bibliographic details and exact annal entries remain to be supplied.
- The Book of Lecan, folio 72, b, column 4: the reference given for the Roscommon genealogy.
- Roderic O’Flaherty, Ogygia, part 3, chapter 93: the reference given for the territorial name Tír Tuathail.
- Southeran (1871), pp. 73 and 85: references given for Roscommon landholding and Fermanagh dispossession. The earlier article does not provide a full title or edition.
- Annals of the Four Masters: cited in the earlier article for McManus history, without specific entries.
- Phillip McManus, McManus Clan Association: the attributed family comment above; no publication date or source link was recorded.
- McManus research at Mexlist.
- Belle Isle Estate.
- McManus surname distribution at Forebears: a distribution resource, rather than evidence of descent from a particular sept.