The Third Section of His Imperial Majesty's Own Chancellery was a secret-police department set up in Imperial Russia. As a successor organisation to the Tayny Prikaz of 1654 to 1676, to the Privy Chancellery of 1686 to 1801, and to the Specialty Chancellery, it effectively served as the Imperial régime's secret police for much of its existence. The organization was relatively small. When founded in July 1826 by Emperor Nicholas I it included only sixteen investigators. Their number increased to forty in 1855. The Third Section disbanded in 1880, replaced by the Police Department and by the Okhrana.