Fawzia Fuad, Empress of Iran. Daughter of King Fouad I of Egypt, sister to King Farouk I of Egypt and first wife to Shah Mohammad Reza Pahlavi of Iran. She could have been a movie star, she looks like Janet leigh of Gone with The Wind!
For my money -- this portrait does Letizia no favors. She's so stunning and this just does not convey that in any way whatsoever. Royal Oil Portraits Paintings by Spanish Artist Richardo Sanz: Prince Felipe and Princess Letizia.