Ó Néill is the original Irish Gaelic form of the surname commonly anglicized as O'Neal. It is derived from the Irish phrase Ó Néill, meaning "descendant of Neil." The personal name Neil ultimately traces back to the Old Irish name Niall, the etymology of which is contested. Possible roots include the Celtic *nītu- ("fury, passion") or the Old Irish nia ("hero"), while a derivation from nél ("cloud") has also been proposed. Historically, Niall was the name of several early Irish kings, most notably Niall of the Nine Hostages, a semi-legendary 4th–5th century High King. The Ó Néill surname is intimately tied to the powerful O'Neill dynasty (Irish: Ó Néill), a lineage of Irish Gaelic origin that was historically among the most prominent families of the Northern Uí Néill, alongside the O'Donnell dynasty. The dynasty traces its descent from Niall Glúndub, a 10th-century High King of Ireland, and takes its name from him. From 1232 until 1616, the O'Neills were the sovereign kings of Tír Eoghain, a territory spanning much of modern Ulster, including present-day County Tyrone, parts of County Londonderry, and County Antrim. The surname Ó Néill has numerous variants and anglicized forms, reflecting its spread and adaptation over time. Common related names include Neil, O'Neill, O'Neal, McNeill, and Mac Néill. The Scottish and English forms like Neil and Neal also stem from the same root. Through Norse intermediaries and Norman influence, the name spread to England, Scotland, and Scandinavia. Meaning: "Descendant of Neil" Origin: Irish Gaelic (Ó Néill) Type: Surname Usage Regions: Primarily Ireland, associated with Ulster and the O'Neill dynasty