Many demonstrators in Iran have been calling for the return of Reza Pahlavi, the exiled son of Iran's last shah (king).
Pahlavi himself has called for people to take to the streets. So who is the former crown prince and how much support does he have?
Groomed from birth to inherit Iran's Peacock Throne, Reza Pahlavi was undergoing fighter pilot training in the United States when the 1979 revolution swept away his father's monarchy.
He watched from afar as his father, Mohammad Reza Shah Pahlavi - once backed by Western allies - struggled to find refuge in another country and ultimately died of cancer in Egypt.
The sudden loss of power left the young crown prince and his family stateless, reliant on a dwindling circle of royalists and well-wishers in exile.
