The Qajar dynasty was a ruling dynasty in Iran that lasted from 1789 to 1925. Founded by Agha Mohammad Khan Qajar, it emerged after the decline of the Safavid dynasty. The Qajars were known for their efforts to centralize power and modernize the country, although they faced significant challenges, including foreign intervention and internal strife. During the Qajar period, Iran experienced significant social and political changes, including the rise of nationalism and the Constitutional Revolution of 1905-1911. The dynasty's rule ended when Reza Shah Pahlavi overthrew the last Qajar king, marking the beginning of the Pahlavi dynasty.