Siobhán Maguire (died 1600) was a Gaelic Irish noblewoman, perhaps best known as the biological mother of Hugh O'Neill, Earl of Tyrone.
[6] Historian John O'Hart referred to Cormac and Art as illegitimate (i.e. not Siobhán's children).
[8] Matthew was killed in 1558[9][1] by Shane's foster family,[10][11] placing heirs Brian and Hugh in a dangerous situation.
[1] Her third husband was Eoin McToole O'Gallagher,[16][1] chief advisor to the O'Donnell clan of Tyrconnell.
[17] O'Gallagher was a major adherent to tanist Hugh Roe O'Donnell during the 1580–1592 Tyrconnell succession dispute.
[17][18] In 1588 O'Gallagher went to Lord Deputy William FitzWilliam on a promise of safe conduct, but he was imprisoned instead.