Brian MacArt O'Neill was a member of theO'Neill Dynasty, the leadingGaelic family ofUlster. He was the son and heir ofArt MacBaron O'Neill ofOneilland and a grandson ofMatthew O'Neill, 1st Baron Dungannon. He may have taken part inTyrone's Rebellion, a conflict in which several of his brothers were killed. Along with the rest of his family he waspardoned as part of theTreaty of Mellifont in 1603.
In 1607 he was arrested on a charge ofmurder. Because it was unlikely that ajury inCounty Armagh, where many people remained frightened of the O'Neills, would convict him it was decided to try him inDublin instead. Despite attempts by his powerful and influential uncleHugh O'Neill, Earl of Tyrone to have him pardoned the sentence was still set to be carried out. Tyrone reportedly offered a bribe of £500 to secure his release, which was refused.[1]
The steadfast refusal of theViceroy of Ireland SirArthur Chichester to overturn the death sentence, convinced Tyrone that his power was being weakened despite his generally good relations withJames I inLondon. This was a factor in his decision to take part in theFlight of the Earls which took him into exile in Italy.[2] The Earl's departure sealed the fate of Brian who was hanged on the reduced charge ofmanslaughter.[3]
Three of his brothers served asmercenaries in theSpanish Army. The best-known of them wasOwen Roe O'Neill.[citation needed]
