Conrad Fulke Thomond O'Brien-ffrench was born in London, England, the second son of Henry Albert De Vreque O'Brien-ffrench, Marquis de Castelthomond, and his wife Winifred neé Thursby, heiress and daughter of Major James Legh Thursby, of Ormerod House Lancashire [REF].
He and his elder brother Rollo (Rollo Adrien Vladimir Thursby Marie Altieri O'Brien-ffrench) spent their early childhood in Italy at Villa Torlonia (Frascati) in the Alban Hills, east of Rome, and then at Piazza dell'Indipendenza in Florence, where they received private tutoring in English, French and Italian [REF].