Northern Uí Néill in the context of "Tyrconnell"

Tír Eoghain (meaning Land of Eoghan), also known as Tyrone, was a kingdom and later earldom of Gaelic Ireland, comprising parts of present-day County Tyrone, County Armagh, County Londonderry and County Donegal (Raphoe). The kingdom represented the core homeland of the Cenél nEógain people of the Northern Uí Néill and although they ruled, there were smaller groups of other Gaels in the area. One part of the realm to the north-east broke away and expanded, becoming Clandeboye, ruled by a scion branch of the O'Neill dynasty. In one form or another, Tyrone existed for over a millennium. Its main capital was Dungannon, though kings were inaugurated at Tullyhogue Fort.

Upon its foundation in the 5th century, Tyrone was a sub-kingdom of the larger Aileach, which represented the powerbase of the Uí Néill (descendants of Niall of the Nine Hostages) in the north of Ireland. The territory of Eoghan mac Néill was initially based in Inishowen and expanded out from there under his descendants. Periodically, during the time of Aileach, the leaders of Tyrone established themselves as High Kings of Ireland, providing in total of thirteen High Kings from the 6th to the 10th centuries. The first was Muirchertach mac Muiredaig and the last from this period was Domnall ua Néill. Three later Tyrone claimants to the High Kingship were Domnall Ua Lochlainn and Muirchertach Mac Lochlainn in 12th century and finally Brian Chatha an Dúna O'Neill in the 13th century.

The O'Neill dynasty (Irish: Ó Néill) are a lineage of Irish Gaelic origin that held prominent positions and titles in Ireland and elsewhere. As kings of Cenél nEógain, they were historically one of the most prominent family of the Northern Uí Néill, along with the O'Donnell dynasty. Some O'Neills state that their ancestors were kings of Ailech during the Early Middle Ages, as descendants of Niall of the Nine Hostages.

Two of their progenitors were High Kings of Ireland: Niall Glúndub (from whom they take their name) and Domnall ua Néill. From 1232 until 1616, the O'Neills were sovereign kings of Tír Eógain, holding territories in the north of Ireland in the province of Ulster, particularly around modern County Tyrone, County Londonderry and County Antrim, in what is now Northern Ireland. After their territory was merged with the Kingdom of Ireland and the land was caught up in the Plantation of Ulster, they were involved in a number of events, such as Tyrone's Rebellion, the Flight of the Earls, the Irish Rebellion of 1641 and the Irish Confederate Wars.

Tyrconnell (Irish: Tír Chonaill, meaning 'Land of Conall'), also spelled Tirconnell and Tirconaill, was a kingdom of Gaelic Ireland. It is associated geographically with present-day County Donegal, which was officially named County Tirconaill between 1922 and 1927. At times it also included parts of County Fermanagh, County Sligo, County Leitrim, County Tyrone and County Londonderry at its greatest extent. The kingdom represented the core homeland of the Cenél Conaill people of the Northern Uí Néill and although they ruled, there were smaller groups of other Gaels in the area.

From the 5th century founding of Cenél Conaill, the tuatha was a sub-unit of the larger kingdom of Ailech, along with their Cenél nEógain cousins, fellow descendants of Niall of the Nine Hostages. Their initial ascent had coincided with the decline of the Ulaid, whose kingdom of Ulster receded to the north-east coast. In the 12th century the kingdom of Ailech split into two sovereign territories and Cenél Conaill became Tír Chonaill under the Ó Domhnaill (O'Donnell) clan. It was the location of fighting during the Nine Years' War (Ireland) at the end of the 16th century. It continued to exist until the 17th century when it was incorporated into the English-ruled Kingdom of Ireland following the Flight of the Earls.

Donegal (/ˌdʌnɪˈɡɔːl, ˌdɒn-, ˈdɒnɪɡɔːl/ DUN-ig-AWL, DON-, DON-ig-awl; Irish: Dún na nGall [ˈd̪ˠuːnˠ n̪ˠə ˈŋal̪ˠ], "fort of the foreigners") is a town in County Donegal in Ulster, the northern province in Ireland. Although Donegal gave its name to the county, now Lifford is the county town. From the 15th until the early 17th century, Donegal was the "capital" of Tyrconnell, a Gaelic kingdom controlled by the O'Donnell dynasty of the Northern Uí Néill. The town is in a civil parish of the same name.

Donegal is in South Donegal and is located at the mouth of the River Eske and Donegal Bay, which is overshadowed by the Blue Stack Mountains ("the Croaghs"). The Drumenny Burn, which flows along the eastern edge of Donegal Town, flows into the River Eske on the north-eastern edge of the town, between the Community Hospital and The Northern Garage. The Ballybofey Road (the R267) crosses the Drumenny Burn near where it flows into the River Eske. The town is bypassed by the N15 and N56 roads. The centre of the town, known as The Diamond, is a hub for music, poetic and cultural gatherings in the area. There is a memorial to the Four Masters in the centre of the Diamond.

The Grianán of Aileach (/ˌɡriːnən əv ˈæljə(x)/ GREE-nən əv AL-yə(kh); Irish: Grianán Ailigh [ˌɟɾʲiənˠaːnˠ ˈalʲiː]), sometimes anglicised as Greenan Ely or, locally, as Greenan Fort, is a hillfort atop the 244 metres (801 ft) high Greenan Mountain at Burt on the Inishowen Peninsula in County Donegal, Ireland. The main structure is a 19th-century reconstruction of a stone ringfort, thought to have been built by the Northern Uí Néill, in the sixth or seventh century CE; although there is evidence that the site had been in use before the fort was built. It has been identified as the seat of the Kingdom of Ailech and one of the royal sites of Gaelic Ireland. The wall is about 4.5 metres (15 ft) thick and 5 metres (16 ft) high. Inside it has three terraces, which are linked by steps, and two long passages within it. Originally, there would have been buildings inside the ringfort. Just outside it are the remains of a well and a tumulus.

By the 12th century, the Kingdom of Ailech had become embattled and lost a fair amount of territory to the invading Normans. According to Irish literature, the ringfort was mostly destroyed by Muirchertach Ua Briain, King of Munster, in 1101.