This is a Y-chromosomal project for Mac Giolla Ghunna families and Anglicised variants. The aims of the project are: 1. to make connections between Mac Giolla Ghunna's worldwide. 2. to establish that the surname originated from Clan Mag Uidhir. 3. to establish that the surname originated from Ossory FitzPatrick's. (No) 4. to further understand if the the Mac Giolla Ghunna in turn originated from the 3 Collas. The surname originates in Ireland in the counties of Fermanagh, Cavan and Leitrim. A prominent holder of the surname was Cathal Buí Mac Giolla Ghunna, a Gaelic language poet in the early 18th century whose most famous work was An Bonnán Buí (The Yellow Bittern). Based on Y-SNP relations, the name could be descended from MacDomhnaill Clainn Ceallaigh from South East Fermanagh. The terminal SNP characteristic of the Mac Giolla Gunna, BY20937, is similar to other Fermanagh, Clankelly Barony surnames that claim descent from Domhnall, grandson of Ceallach, king of the Ui Chremthainn d. 732: McDonnells (latterly the McGonnells & McConnells), O'Lorcans, some O'Flanagans (Boylan), O'Kellys, O'Donnellans, O'Kerans (Kearns), and O'Harts & MacMaolruanaighs (Mulrooney/Rooney). See Donald M. Schlegel (2005) MacDomhnaill Clainn Ceallaigh. Clogher Record 18(3): 437-466. The line is distinct from Caithness Clan Gunn. Though, one of the Anglicisations of Mac Giolla Ghunna is Gunn.