Lord Edward O'Brien British Royal Navy officer (died 1824) (1769–1824) Parents Mary Carrick Edward Dominic O'Brien Children James O'Brien Henry O'Brien unknown son O'Brien Siblings James O'Brien, 3rd Marquess of Thomond Murrough O'Brien John O'Brien Harriet O'Brien Mary O'Brien William O'Brien, 2nd Marquess of Thomond Partners Gertrude Methuen Lady Elizabeth Somerset