an Irish king of the O'Neill dynasty of Ulster in the mid 16th century.
Shane O'Neill's career was marked by his ambition to be The Ó Néill Mór – Sovereign of the dominant Ó Néill Mór family of Tyrone... and thus head overking or Rí ruirech of the entire province. This brought him into conflict with competing branches of the O'Neill family and with the English government in Ireland, who recognised a rival claim. Shane's support was considered worth gaining by the English even during the lifetime of his father Conn O'Neill, 1st Earl of Tyrone. But rejecting overtures from Thomas Radclyffe, 3rd Earl of Sussex, the lord deputy from 1556, Shane refused to help the English against the Scottish settlers on the coast of Antrim, allying himself instead with the MacDonnells, the most powerful of these immigrants