Prince David Chavchavadze was a CIA agent during the cold war who was descended from Tsar Nicholas I of Imperial Russia and became friendly with Stalin's daughter Prince David Chavchavadze, who has died aged 90, was descended from the royal families of both Russia and Georgia, and served as a cold war case officer with the CIA for 25 years; he later made his mark as a writer and historian... Prince David Chavchavadze, born May 20 1924, died October 5 2014