Reza Shah Pahlavi (previously Reza Khan; 15 March 1878 – 26 July 1944) (Persian: رضاشاه پهلوی [ɾeˈzɒː ˈʃɒːhe pʰæɦlæˈviː]) was an Iranian military officer and monarch who was the founder of the Pahlavi dynasty and Shah of Iran from 1925 to 1941. Originally an army officer, he became a politician, serving as minister of war and prime minister of Iran, and was elected shah following the deposition of Ahmad Shah, the last monarch of the Qajar dynasty.
Joining the Persian Cossack Brigade at age 14, he rose through the ranks, becoming a brigadier-general by 1921. In February 1921, as leader of the entire Cossack Brigade based in Qazvin province, he marched towards Tehran and seized the capital. He forced the dissolution of the government and installed Zia ol Din Tabatabaee as the new prime minister. Reza Khan's first role in the new government was commander-in-chief of the army and the minister of war. Two years after the coup, Seyyed Zia appointed Reza Pahlavi as Iran's prime minister, backed by the compliant national assembly of Iran. In 1925, the constituent assembly deposed Ahmad Shah Qajar, the last Qajar shah, and amended Iran's 1906 constitution to allow the election of Reza Pahlavi as the Shah of Iran. He founded the Pahlavi dynasty that lasted until it was overthrown in 1979 by the Iranian Revolution.