O Dennehy or O Denny - Irish / Ua Duineacha / Duineachdha. A Sept / Family branch, who had their territory in Co. Kerry in the south - west and Co. Cork in Desmond / Des Mhumhain / Southern Munster and nearby in Co. Waterford in the south - east of the Munster Province.

O Dennery - Irish.  A Sept / Family branch, who had their territory in Co. Mayo and Co. Roscommon in the Connacht Province.

Dennes -

O Dennigan or O Denegan. Used as variants for O Donegan, which see, in the Connacht Province.

O Dennis - Irish / Ua Donnghusa. A Sept / Family branch, who had their territory in Co. Cork in Des Mhumhain / Desmond / Southern Munster and Co. Dublin in the north - east of Southern Leinster? Also see Denny.

Mac Dennis. From Mac Donagh, which see. Usually known as Dennison in the Ulster Province.

Dennis / le Danei (the Dane). French origins in Co. Cork in Desmond / Southern Munster and Co. Dublin in the north - east of Southern Leinster?

Dennis. French / Dionysius in Co. Cork in Desmond / Southern Munster and Co. Dublin in the north - east of Southern Leinster?

Denny. English origins in Co. Derry in the north - east of the Ulster Province in the 16th Century AD. Cognate with Dennis. Also used in Co. Kerry in the south - west of Desmond / Southern Munster for O Dennehy, which see.

O Denroche - Irish / Ua Duibhinnreachtaigh - innreachtach (lawful). A Sept / Family branch, who had their territory in the Connacht Province. Also known as O Dunroche.

Denvir. They were in Co. Down in the south - east of the Ulster Province.

Derenzy / de Renzi in Co. Dublin and Co. Wexford in the east of Southern Leinster in the early 17th Century AD.

O Dermody - Irish / Ua Diarmada. A Sept / Family branch, who had their territory in Co. Cavan in Southern Ulster and nearby in Co. Westmeath in the north - west of Northern Leinster.

O Dermody - Irish / Ua Diarmada. A Sept / Family branch, who had their territory in Co. Kilkenny in the south - west of Southern Leinster.

O Dermody or O Darmody - Irish / Ua Diarmada. A Sept / Family branch, who had their territory in Co. Galway in Southern Connacht.

O Dermody. A Sept / Family branch, who had their territory in Co. Tipperary and Co. Clare in Northern Munster.

O Dermody or O Dermait  - Irish / Ua Duibhdhiorma or Ua Duryorma. A Sept / Family branch, who were the Chiefs of Breadach at Moville near Inishowen on the western shore of Loch Foyle in Co. Donegal in the north - west of the Ulster Province. Also see next entry.

O Dermond or O Dermott or O Darby - Irish / Ua Duibhdhiorma - dubhdhiorma (black troop). Heremonian Dal Cuinn "northern" Ui Niaill Cenel nEogain Sept / Family branch (Descended from *90.Niall - of the Nine Hostages the 126th King of Tara / Ireland (Ui Niaill) through one of his (8) sons in 91.Eogan (Cenel nEogain) the 1st King of Ailech in Northern Ulster, and then directly through one of his (5) sons, 92.Felim / Feidhlimidh the ancestor of the Ui Duibhdhiorma Sept who was to be the direct male line ancestor of the O Dermond Sept who had their territory at Inishowen in Co. Derry and Co. Donegal in Northern Ulster where they were the Chiefs of Breadach.

Mac Dermot or Mac Dermott - Irish / Mac Diarmada - dia (god) armaidi arms). Heremonian Dal Cuinn Ui Briuin Ai Siol Muireadhaigh Ui Conchobhair Sept / Family branch, who were the Princes / Tanaistes of Moylurg / Mag Luirg in Co. Roscommon, and Co. Sligo in the Connacht Province who were kinsmen to the O Connor Kings of Connacht and the Mac Donoughs the Princes of Tirerril in Co. Sligo. Their direct male line ancestor was 109.Mulrooney Mor / Mael Ruanaid (a brother to 109.Conor / Conchobhar the 44th King of Connacht who is the direct male ancestor of the O Connors in the 10th Century AD who were the Kings of Connacht and Ireland. They also had their kingdom of Moylurg in the north of Co. Roscommon in the east of Connacht, which 109.Mulrooney had received from his brother. 109.Conor. They also had their castle on Mac Dermot’s Island in Loch Key near Boyle, Unfortunately just like so many of the other Gaelic Milesian Family Septs they only survived until the 17th Century AD under the never - ending English confiscations, and their ethnic and religious oppression, when they were to be driven out of their territory there and forced to move to Coolavin near Loch Gara in Co. Sligo in the north - west of Connacht. Their Septs were Mac Dermot Roe / Ruadh - of Red Complexion who had their territory at Kilronan in Co. Galway, and Mac Dermot Gall in the east of Co. Roscommon. (The Mac Dermot the Prince of Coolavin was at one time Niall Mac Dermot).  Ancestors: *37.Eremon the joint Gaelic Milesian 1st King of Ireland, who is the ancestor of all the Heremonian Septs and Kings of Ireland and his descendant *83.Conn - of the Hundred Battles who was the 110th King of Tara / Ireland is the ancestor of all of the Dal Cuinn Septs in Ireland, *84.Art - the Lonely the 112^th King of Ireland, *85.Cormac mac Airt  the 115^th King of Ireland, *86,Cairbre Liffeachair the 117^th King of Ireland, *87,Fiacha Sraibhthine the 120^th King of Ireland, *89.Eochy Mugmedon the 124th King of Tara / Ireland whose son; 

90.Brion was the first Dal Cuinn King of Connacht and the ancestor of all the Hermonian Dal Cuinn Ui Briuin Septs in Ireland. His descendant 98.Reilly / Rogallach was the 12th King of Connacht who is the more directb ancestor of the Ui Briuin Ai Septs the father of 99.Fergus / Muirgius the father of 100. Murray / Muireadach Mullethan the 18th King of Connacht the ancestor of the Siol Muireadhaigh and the father of 101.Indrechtach the 21st King of Connacht the father of 102.Murgal the father of 103.Tomalty / Tommaltach the father of 104.Muirgius the 31st King of Connacht the father of 105.Teague Mor the father of 106.Conor the 38th King of Connacht the father of 107.Cathal the 41st King of Connacht the father of 108.Teague / Tadhg Mor the 42nd King of Connacht the father of 109.Mulrooney / Maol Ruanaidh Mor who was a younger brother of 109.Conor the 44th King of Connacht the direct male line ancestor of the O Connors of Connacht, and was married to a daughter of Flann Abraid O Malley, and was the direct ancestor of the Mulrooneys / Mulroneys / Rooneys / Roneys / Rowneys, and the father of 110.Murtough who was the Prince of Moylurg who married the daughter of O Dowd the northern Ui Fiachrach King of Tyrawley, and was the father of 111.Teague who also had a brother, 111.Mulrooney who is the ancestor of the O Collys, and was also the father of 112.Mulrooney who was his second son, who was the father of 113.Teague Mor the father of

114.Diarmaid the direct male line ancestor of the Mac Dermots / Mheic Diarmada, who had 2 brothers, 114.Donough the ancestor of the O Morris, and 114.Teague Oge the Younger the ancestor of the Mac Laughlins of Connacht, and the father of 115.Conor Mac Dermot who was the first to use their surname, who was the father of 116.Tomalty na Carriga Mac Dermot the father of 117.Cormac Mac Dermot who was the Prince of Moylurg whose brother 117.Donough is the direct male line ancestor of the Mac Donaghs the Princes of Tirerril in Co. Sligo, and the father of 118.Conor Mac Dermot the Prince of Moylurg in 1251 AD who was the father of 119.Giolla Chriosd (Servant of Christ) who had a brother 119.Diarmaid Dall the ancestor of the Mac Dermot Roe / Ruadh of Red Complexion and the father of 120.Mulrooney Mac Dermot the father of 121.Timothy / Tomalty Mac Dermot the father of 122.Conor Mac Dermot the father of 123.Aodh Mac Dermot the father of 124.Rory Caoch Mac Dermot the father of 125.Rory Oge - the Younger Mac Dermot the father of 126.Teague Mac Dermot the father of 127.Rory Mac Dermot the father of 128,Brian Mac Dermot the father of 129.Brian Oge Mac Dermot the father of 130.Turlough Mac Dermot who died in 1640 AD, whose brother 130.Charles Mac Dermot died in 1693 AD, and he also had another brother 130.Teague na nGadhar Mac Dermot. 130.Charles Mac Dermot's son, 131.Hugh / Aodh Mac Dermot who died in 1707 AD was an officer in King James 11's army who was taken prisoner at the Battle of Aughrim in Connacht , who also had a brother, 131.Timothy Mac Dermot the father of 132.Andrew Mac Dermot the father of 133.John Mac Dermot. His son, 134.Charles Mac Dermot died in 1758 AD at Coolavin, and had a brother, 134.Terence Mac Dermot who was an M.P. in James 11's Parliament in Ireland who was also Attainted (Off with his head) by the English, and his son, 135.Myles Mac Dermot died in 1777 AD whose brothers were 135.Terence Mac Dermot, and 135.Hugh Mac Dermot who died in 1824 AD who was the father of 136.Charles Mac Dermot who married Arabella O Rourke, and died in 1873 AD, the father of 137.Hugh Mac Dermot of Coolavin who was a Q.C. J.P. in 1887 AD who was the Chief of the Clann Mac Dermot and the hereditary Prince of Coolavin.  

Fitz Dermot - Normanized - Irish / Mac Giolla Mo - Cholog / Mac Gilla Mocholmac. Heremonian Ui Laoghaire Ui Lughaidh Cu Corb Ui Dunlainge Ui Dunchada Sept who had their territory in Co. Dublin, and in Co. Kildare in Central Southern Leinster. The Ui Dunchada Sept adopted the surname originally of Mac Gilla Mo - Cholmoc and due to their proximity to Dublin in 1170 AD they sided with the Anglo Normans after the Anglo - Norman Invasion and the battle for Dublin and also took up the Norman name of Fitz Dermot (Descended from a son of Dermot). Ancestors: 103. Dunchad the 15th King of Leinster (Ui Dunchada),  102.Murrough / Murchad the 14th King of Leinster, 99.Faelan the 10th King of Leinster, 98.Colman Mor the 6c King of Leinster, 95.Ailill the 6th King of Leinster, 94.Dunlaing (Ui Dunlainge), 92.Bressal Belach the 1st King of Leinster, 90. Cahir / Cathair Mor the 109th King of Tara / Ireland, 86. Cu Corb, 78.Lewy / Lughaidh (Ui Lughaidh), *60.Leary / Laoghaire (Ui Laoghaire) the 68th King of Tara / Erinn,

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