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.

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.

With the creation of the Crown of England's Kingdom of Ireland in the 16th century, Tyrone would be brought into the Tudors' sphere of influence, but was a major source of Gaelic Irish resistance, before, while and after being subordinated.

In the 12th century the kingdom of Ailech split into two sovereign territories and Cenél nEógain became Tír Eoghain, the land of Eoghan, Anglicised as Tyrone.

The King of Tyrone, Conn Bacagh O'Neill, in a personal capacity, carried the sword of state before his uncle Gerald Og FitzGerald, Earl of Kildare when he was made Lord Deputy of Ireland in 1524.

This rumour reached the ear of the young and inexperienced Silken Thomas, who, in reaction, rode through the streets on horseback with his men to St. Mary's Abbey, Dublin, where he cast off sword and robes of state and renounced his allegiance to the English monarchy (his father in London, upon hearing of his young son's rebellion, did in fact die a few days later "of grief").

[4] Silken Thomas rose up in Rebellion and was determined to take Dublin and "avenge" the death of his father: he rallied to his banner a sizeable proportion of Gaelic Ireland, or at least some of the most influential parts of it, this included; the O'Neills of Tyrone (his cousin) and the O'Briens of Thomond, as well as the O'Carrolls of Éile, O'Connor Falys of Offaly and the O'Mores of Laois who backed him up for the attacks on the English Pale.

[4] As the tide began to turn against them, Thomas surrendered to Leonard Grey at Maynooth and was given safe passage to ask for mercy from the King in London but was executed at Tyburn with his uncles in 1537.

[4] This issue was not concluded though, as back in Ireland the Geraldine League was founded in 1539 by the O'Neills of Tyrone, the O'Donnells of Tyrconnell, the O'Briens of Thomond and other clans, to support the claim of the 14-year-old, Gerald FitzGerald to the now forfeited title of the Earldom of Kildare.

This Gaelic alliance under the auspicies of the Geraldine League was able to menace the English Pale, looting and sacking Ardee and Navan, before Conn Bacagh O'Neill and Manus O'Donnell were dealt a thorough defeat at the Battle of Belahoe by Grey and Gerald Aylmer in 1539.

Tyrone was invaded in 1541 by an army under Anthony St Leger, which saw the final defeat of the Geraldine League and the young titular Earl of Kildare fled to Catholic Europe, becoming a Knights Hospitaller.

This offer was opened up to Conn Bacagh O'Neill through St Leger, who accepted and went to London in 1542, pledging allegiance to Henry VIII: he was rewarded handsomely in terms of money and land and was also made Earl of Tyrone.

By this time, Elizabeth I had come to the throne of England and Ireland: she was keen to come to an agreement with Shane O'Neill, if he would submit to her authority and the Lord Deputy.

While the details of the Earldom were to be worked out, Elizabeth I had allowed to call himself The Ó Néill and for Tyrone to collect taxes from uirrithe, which had been abrogated since the days of her father.

[5] Boosted by his new found royal favour, Shane's Tyrone moved against the MacDonnells of Antrim at the Battle of Glentaisie in 1565, claiming to be hammering Her Majesty's Scottish enemies (all the while building power for himself).

During the reign of Stuart monarch James I, Tyrone would be reduced further with the barony of Loughinsholin in its north-east being transferred to the new county of Londonderry.

The people who lived in Tyrone were Irish Gaels (mostly from the Northern Uí Néill but also others), with some Highland Scots mercenaries in later times.

The second most senior clan, also from the Cenél nEógain kindred, were the Ó Catháin (O'Cahan),[12] who ruled a sub-kingdom synonymous with the barony of Coleraine, then known as Fir na Craoibhe.

The O'Cahan held the hereditary honour of holding a shoe over the King of Tyrone's head during their royal inauguration rituals.

The O'Cahans gained power in the 12th century to the detriment of the Ó Conchobhair (O'Connor) of the Ciannachta Glenn Geimin,[12] an Eberian group distantly kindred to the Eóganachta in Munster, who remained in the area subsequently but in much reduced form.