Darnii / Darini - Celts who had their territory in Co. Antrim and Co. Derry in the north - east of the Ulster Province.

Dartraige Sept - (Eastern) were near Enniskillen in Co. Fermanagh in the south - west of the Ulster Province near Newtown Butler.

Dartraige Sept - (Western) in the south - west of the Ulster Province.

Deagades - A Heremonian Muscraige sub - Sept of the Earnan Sept in the Munster Province.

Deisi - Decies - Deise - A Heremonian Sept descended from *81.Angus - Oengus "Gaibuaibthech" - of the Poisonous Spear aka 82.Angus "Bolg" who in 265 AD was involved in a dispute with is kinsmen 82.Cormac mac Airt the 115th Heremonian Dal Cuinn King of Tara - Ireland at Tara in Mide - Meath in Northern Leinster killing 82.Cormac's, 83.Kelly - Cellach and blinding 82.Cormac in one eye so that he had to eventually withdraw from Tara as the King due to the blemish. He was a son of 80.Fiacha "Suighdhe,” another son of 79.Felim "Reachtmar" - The Lawgiver - the 108th King of Tara - Ireland who was the father also of 80.Conn of the Hundred Battles the 110th King of Tara - Ireland and direct ancestor of the Dal Cuinn Sept. They had their original territory in Brega to the south - west of Tara in Co. Meath in the north - east of the Leinster Province. After 7 more battles they were then driven from Mide - Meath by 82.Cormac and settled in the Dungarvon region in Co. Waterford in the north - east of the Munster Province, which became Deisi Mumhan between the River Blackwater and the River Suir in the region still known as "The Decies" above Ardmore with Lismore to the south - west on the River Blackwater. In 746 AD Muirgius was their King, who was a son of Fergus - Fearghus. Deisi Temro - They later conquered the territory in the south of Ossory in Co. Kilkenny in the south - west of Leinster assisted by the Ithian Corca Loigde Septs. The original Heremonian battle in Meath may have been over sovereignty.

Tuatha De Danann - A Scythian Nemedian Celtic Sept who gained control in Ireland over their kinsmen the Fir Bolg Septs and then lost control of Ireland in the 16th Century BC to the Gaelic Milesian Septs.

Ui Dego - A Heremonian Cu Corb Sept directly descended from 94.Daig, one of the 3 sons of 93.Labraid "Laidech," one of the 2 sons of 92.Bressal "Belach" the Cu Corb first King of Leinster, a son of 91.Fiachu "Ba hAiccid" - The Lame - who was one of the 9 sons of 90.Cahir - Cathair "Mor" the 109th King of Tara - Ireland descended from 86.Cu "Corb" the direct ancestor of the Cu Corb Septs in Leinster. Their territory was inland from the east coast below their kinsmen the Cu Corb Ui Enechglais Sept near Arklow and above their other kinsmen, the Cu Corb Ui Cheinnselaig Sept at Ferns and to the north - west of Arklow.

Delbna - of Iar (West) in Co. Galway in the south - west of the  Connacht Province.

Delbna Bethra - territory below Clonmacnoise in Co. Offaly in mid - north - west of the Leinster Province, in the region of the Heremonian Dal Cuinn "Southern" Ui Niaill Cenel Fiachach whose territory crossed over the River Brosna to Durrow in the east. 

Delbna - East - was further to the east near Co. Roscommon in the east of the Connacht Province.

Delbna Mor Sept - Had their territory above the Fir Bile Sept but below the Heremonian Dal Cuinn "Southern" Ui Niaill Caille Follamain Sept in Central Mide - Northern Leinster with the Heremonian Dal Cuinn "Southern" Ui Niaill Cenel nArdgail Sept to the south - east and the Heremonian Dal Cuinn "Southern" Ui Niaill Cenel Loegaire Sept to the east.

Delbna Nuadat - territory to the west of Loch Ree between the River Shannon and the River Suck below Roscommon with Athlone to the south - east.

Delbna Tire da Locha Sept - had their territory in the far - south - west region of Loch Corrib below the Conmaicne Mara Sept  and the Partraige Sept in Co. Galway in  Southern Connacht.