O Flanagan - Irish / Ua Flannagain - flann (red or ruddy). Important Heremonian Dal Cuinn Ui Briuin Ai Sept / Family branch of the Siol Muireadhaigh / Sil Murray Ui Conchobhair Tuath / Family region who were kinsmen to the O Connor Kings of Connacht and Ireland with their territory originally in parts of Co. Fermanagh in the south - west of the Ulster Province and nearby in Co. Roscommon in the east of the Connacht Province where they were Chiefs and Kings. They were also nearby in Co. Offaly in the north - west of Southern Leinster. Ancestors: 106.Conor / Conchobar the 38th King of Connacht (Ui Conchobair), 105.Tadg Mor, 104.Muirgius the 31st King of Connacht, 101.Indrechtach the 21st King of Connacht, 100.Murray / Muireadach Muillethan the 18th King of Connacht (Siol Muireadhaigh), 99.Fergus / Fergusa / Muirgius, 98.Reilly / Raghallach the 12th King of Connacht (Ui Briuin Ai) 90.Brion the first Dal Cuinn King of Connacht (Ui Briuin), *83.Conn of the Hundred Battles the 110th King of Tara / Ireland (Dal Cuinn).

O Flanagan - Irish / Ua Flannagain. Heremonian Dal Cuinn "southern" Ui Niaill Cenel Cairbre Sept / Family branch from the Tuath Ratha / Toora, who had their territory in Co. Fermanagh in the south - west of the Ulster Province. Ancestors: *93.Toole / Tuathal Mael Garb the 132nd King of Tara / Ireland, 92.Cormac Caech, 91.Cairbre / Coirpre, *90.Niall - of the Nine Hostages the 126th King of Tara / Ireland (Ui Niaill), *83.Conn of the Hundred Battles the 110th King of Tara / Ireland (Dal Cuinn).

O Flanagan - Irish / Ua Flannagain. Heremonian Dal Cuinn Colla Da Crioch Siol Daim Argait (Ui Cremthainn) Clan Kelly / Ceallaigh Sept / Family branch, who had their territory in Co. Monaghan in Southern Ulster. (Descended from Flanagan O Donnell of the Clan Kelly.) Kinsmen to the Mac Donnells / Mheic Domhnaill the Kings of Clan Kelly / Clann Ceallaigh who had their territory nearby at Lisnakea in Co. Fermanagh in the south - west of the Ulster Province. Ancestors: Flanagan O Donnell, 96. Kelly, 95.Daimine, 94.Cairpre Dam Argait, 93.Eochu / Echach, 92.Criffan / Crimthann Lethan, 91.Fiacc, 90.Daig Duirn, *89.Rochadh, 88.Murray / Muireadach Colla Da Crioch / Focrith - of the Two Countries, 87.Eochy / Echu Doimhlen, *86.Cairbre Liffeachair the 117th King of Tara / Ireland.

O Flanagan of Co. Offaly. Heberian Cianacht Cenel nAga Sept / Family branch who had their territory at Kinelargy / Barony of Ballybritt. Ancestors: *84.Ailill Oluimm the Heberian 1st King of Munster. 85.Cian the direct male line ancestor of the Cianachta Septs and younger  brother of 85.Eoghan Mor (Eoghanachta) and 85.Cormac Cas (Dal gCais) and the father of 86.Teague / Tadhg the father of 87.Conla, whose brother 87.Cormac Galeng is the direct male line ancestor of the O Haras of Co. Sligo and Co. Mayo in their kingdom of Leyney in the Connacht Province, the O Caseys, the O Brogans, the O Downs, the O Henaghans and the O Hallys, and was the father of 88.Iomchadh Uallach, who also had a brother 88.Fionnachta the ancestor of the O Meaghers / O Mahers, and was the father of 89.Sabhran the father of 90.Iomchadh, ancestor of the O Carrolls of Ely, whose brother 90.Fec / Feigth is the ancestor of the O Flanagans of Ely and the Cianacht O Connors of Cianacht / Keenaught in Co. Derry in the north - east of the Ulster Province, 90.Fionnachtach, 91.Neachtan, 92.Maolfabhal, 93.Donsliebhe, 94.Arga the direct male line ancestor of the Cinel nArga, 95.Aongus, 96.Flannagan the direct male line ancestor of the O Flanagans / Ui Flannagain Ele, 97.Ceanfaoladh, 98.Lorcan, 99.Donnell, 100.Macniadh, 101.Mughron, 102.Diarmaid, 103.Cucalma O Flannagain.

O Flanagan. A Sept / Family branch, who had their territory in Co. Waterford in the south - east of the Munster Province.

O Flanagan - Irish / Ua Flannagain. A Sept / Family branch who were the Chiefs of Comar near O Breen's / Ui Braoin Country in Midhe in Northern Leinster.

O Flanahy - Irish / Ua Flannchaidh. A Sept / Family branch, who had their territory in the Heberian kingdom of Tuaisceart Mhumhain /  Thomond / Northern Munster.

O Flannelly - Irish / Ua Flannghaile - flann (red ) ghaile (valour). A Sept / Family branch who were Kings and had their territory in Co. Sligo in the north - west of the Connacht Province. Often confused with O Flannery.

O Flannery - Irish / Ua Flannabhra - flann (red) - abhar (eyebrows). Heremonian Dal Cuinn Ui Fiachrach Sept / Family branch, who had their territory in Co. Mayo in the mid - west of the Connacht Province. Ancestors: 90.Fiachra the second Dal Cuinn King of Connacht (Ui Fiachrach), *89.Eochy Mugmedon the 124th King of Tara / Ireland, *83.Conn of the Hundred Battles the 110th King of Tara / Ireland (Dal Cuinn). *37.Eremon (Heremonians.)

O Flannery - Irish / Ua Flannabhra - flann (red) abhar (eyebrows). Heberian Eoghanacht Ui Fidhgheinte Sept / Family branch who were the Chiefs of the Dal Cairbre Eva Sept with the O Clerkins, in their territory in the Barony of Kenry in Co. Limerick in the mid - north - west of Thomond / Tuaiscert Mhumhain / Northern Munster. Ancestors: 91.Cairbre / Coirpre ancestor of the Ui Coirpre Aebda Sept, 90.Brion ancestor of the Ui Fidgeinti Sept, 89.Fiachu Fidgennid, 88.Maine Munchain, 87.Ailill Fland Bec, 86.Fiachu Mullethan, 85.Eoghan Mor (Eoghanachta), 84.Ailill Oluimm the 1st King of Munster. *37.Heber Fionn (Heberians,)

Flatesbury or Flattesbere or Flatesbery or  Flattesberry. English origins in Co. Dublin in the north - east of Southern Leinster and Co. Kildare in Central Southern Leinster in the early 14th Century AD.

O Flatley - Irish / Ua Flaithfhileadh. Later Ua Flaitile - flaith (prince) fhileadh (poet). Heremonian Dal Cuinn Ui Fiachrach Sept / Family branch, who had their territory in Co. Sligo in the north - west of the Connacht Province. Confused with O Flattery. Ancestors: 90.Fiachra the second Dal Cuinn King of Connacht (Ui Fiachrach), *89. Eochy Mugmedon the 124th King of Tara / Ireland, *83.Conn - mof the Hundred Battles the 110th King of Tara / Ireland (Dal Cuinn).

O Flattery - Irish / Ua Flaitre. Heberian Dal gCais Ui Bloid Sept / Family branch who had their territory in Co. Clare in the north - west of Thomond / Tuaiscert Mhumhain / Northern Munster who were the Dalcassian Chiefs of Fianchora with the O Cahills. Ancestors: 92.Blood / Blod (Ui Bloid), 91.Cas the King of Northern Munster / Thomond (Dal gCais), *37.Eber Fionn (Heberians).