Art MacBaron ( his middle name a reference to the title of his father ) ruled over Oneilland south of Lough Neagh .
He was the half - brother of Brian O'Neill , Cormac MacBaron O'Neill and Hugh O'Neill , Earl of Tyrone .
half - brother   ( half - brother 's middle name a reference to the title of his father ) ruled over Oneilland south of Lough Neagh .
He was the half - brother of Brian O'Neill , Cormac MacBaron O'Neill and Hugh O'Neill , Earl of Tyrone .