Two years after the 1921 Persian coup d'état, led by Zia ol Din Tabatabaee, Reza Pahlavi became Iran's prime minister. The appointment was backed by the compliant national assembly of Iran. In 1925, Reza Pahlavi was appointed as the legal monarch of Iran by decision of Iran's constituent assembly. The assembly deposed Ahmad Shah Qajar, the last Shah of the Qajar dynasty, and amended Iran’s 1906 constitution to allow selection of Reza Pahlavi. He founded the Pahlavi dynasty that lasted until overthrown in 1979 during the Iranian Revolution. Reza Shah introduced many social, economic, and political reforms during his reign, ultimately laying the foundation of the modern Iranian state.