While in Paris, Ionescu fell in love with an Englishwoman named Bessie Richards, whom he met a charity event, and to whom he dedicated his PhD thesis ("La recherche de la paternité naturelle", "Research into Natural Parenthood"). After consulting international law on the matter of marriage, he decided it was best if he were to marry her in Britain. They sealed their union in a common law marriage in Brighton, and later through an Eastern Orthodox religious ceremony in London (November 1881). The couple were to settle in Bucharest, but made frequent visits to Bessie's native country for the rest of her life.