The Imperial State of Iran (Persia) was the state under the Pahlavi dynasty that ruled Iran from the crowning of Reza Shah Pahlavi in 1925 to the overthrow of Reza Shah Pahlavi's son Mohammad Reza Pahlavi in the Iranian Revolution of 1979.
Its collapse marks a break in the ancient tradition of Iranian monarchy. Today, the Pahlavi Dynasty flag is used by Iranian political dissidents, secularists, and republicans.