The Imperial state of Iran, the government of Iran during the Pahlavi dynasty, lasted from 1925 to 1979. During that time two monarchs — Reza Shah Pahlavi and his son Mohammad Reza Shah Pahlavi — employed secret police, torture, and executions to stifle political dissent. The Pahlavi dynasty has sometimes been described as a "royal dictatorship", or "one-man rule". According to one history of the use of torture by the state in Iran, abuse of prisoners varied at times during the Pahlavi reign.