O'Neill dynasty

O'Neill Ó Néill

Parent house	Cenél nEógain
Titles	High Kings of Ireland Kings of Tara Kings of Ulster Kings of Ailech Kings of Tyrone Sept titles: Ó Néill Mór O'Neill of Clandeboye O'Neill of the Fews International titles: Dux Hibernicorum Prince of Ulster Prince of Tyrone Prince of Clanaboy Prince of the Fews Earl of Tyrone Count of Tyrone Marquis del Norte Viscount O'Neill Baron Dungannon
Founded	Late 10th century
Founder	Flaithbertach Ua Néill
Final ruler	Aodh Mór Ó Néill
Current head	By sept Chief

Sept titles:

International titles:

The O'Neill dynasty (Irish: Ó Néill) is a group of families, ultimately all of Irish Gaelic origin, that have held prominent positions and titles in Ireland and elsewhere. As Chiefs of Cenél nEógain, they are historically the most prominent family of the Northern Uí Néill, along with the O'Donnell and O'Doherty. The O'Neills hold that their ancestors were Kings of Ailech during the Early Middle Ages, as descendants of Niall of the Nine Hostages.

A number of their progenitors and members are named as High Kings of Ireland, such as Niall Glúndub (from whom they take their name) and Domnall ua Néill. From 1185 until 1616, the O'Neills were sovereign Kings of Tír Eógain, holding territories in the north of Ireland; particularly around what is today County Tyrone. After their realm 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 significant events, such as Tyrone's Rebellion, the Flight of the Earls, the Irish Rebellion of 1641 and the Irish Confederate Wars.