Henry O'Brien, Lord Ibrackan Irish politician (1642–1678) Parents Henry O'Brien, 7th Earl of Thomond Lady Anne O'Brien Children Katherine O'Brien, Baroness Clifton (of Leighton Bromswold) Donogh O'Brien, Lord Ibracken Mary O'Brien George O'Brien Siblings Henry Horatio O'Brien, Lord O'Brien Lady Auberie Anne Penelope O'Brien Lady Elizabeth O'Brien Lady Mary O'Brien Partners Katherine Stuart, Baroness Clifton (of Leighton Bromswold)