Norman Cohn, 92; British historian studied medieval sects, tyrants

The experience informed his most influential book. Published in 1957, "Pursuit of the Millennium: Revolutionary Millenarians and Mystical Anarchists of the Middle Ages" drew parallels between millenarian movements in the Middle Ages and the rise of 20th-century totalitarianism. He argued that Nazism and Communism drew from the same well of popular mythology as earlier apocalyptic movements such as the Flagellants and the Anabaptists.

In 1995, the Times Literary Supplement ranked "Pursuit of the Millennium" one of the 100 most influential nonfiction books since the war.

Cohn's other books include "Warrant for Genocide" -- an account of the notorious anti-Semitic forgery "Protocols of the Elders of Zion"-- and "Europe's Inner Demons," a study of witch hunts through the ages.