Leila Pahlavi, the youngest daughter of the deposed shah of Iran, has died in London at the age of 31.
Pahlavi died Sunday night, apparently of the rare disease myalgic encephalomyelitis.
Her brother, Crown Prince Reza Pahlavi, in a statement from his Falls Church, Va., office, said: "It brings me enormous pain and deep sorrow to announce the tragic passing away of my beloved sister, Princess Leila Pahlavi, after a lengthy illness."
Princess Leila's family fled Iran in 1979 during the Islamic takeover of the country by the Ayatollah Khomeini. Her father, the late Shah Mohammed Reza, died in 1980, and her mother, Farah Pahlavi, lives in Paris.
The princess, who had been living modestly in a central London hotel, spent many years in the United States. A few years ago, then living in Greenwich, Conn., she told People magazine that it never bothered her that Americans ignored her royal title.
"When you've been through what we have," she said, "formality isn't what counts. . . . I want to see Iran again, but I
love America. I can go anywhere and not worry that people will recognize me and say, 'Did you see that? Did you see how she ate her French fries?' "
Pahlavi graduated from Brown University in 1992. Although the family lost many of its riches, she and her mother and three siblings remained wealthy enough that she did not have to work. She had not married.
Pahlavi is expected to be buried in Paris' Passy cemetery, where her grandmother, Farideh Diba, was recently buried.