The Imperial State of Iran, officially known as the Imperial State of Persia until 1935 and commonly referred to as Pahlavi Iran, was the Iranian state under the rule of the Pahlavi dynasty. The Pahlavi dynasty was created in 1925 and lasted until 1979 when it was ousted as part of the Iranian Revolution, which ended the Iranian monarchy and established the Islamic Republic of Iran.
The Pahlavis came to power in 1925 with the ascension to the throne of Reza Shah, a former brigadier-general of the Persian Cossack Brigade, and the overthrow of Ahmad Shah Qajar, the last Iranian ruler under the Qajar dynasty. Iran's Majlis, convening as a constituent assembly on 12 December 1925, deposed the young Ahmad Shah Qajar and declared Reza Shah as the new shah of the Imperial State of Persia. In 1935, Reza Shah asked foreign delegates to use the endonym Iran instead of the exonym Persia when addressing the country in formal correspondence. Reza Shah declared Iran neutral during the Second World War. Nonetheless, Iran was occupied by British and Soviet forces following the Anglo-Soviet invasion of Iran. Subsequently Reza Shah was forced to abdicate.