Following the establishment of the Republic of Turkey in 1923, some Kurdish and Zaza tribes, which were feudal (manorial) communities led by chieftains (''agha'') during the Ottoman period, became discontent about certain aspects of Atatürk's reforms aiming to modernise the country, such as secularism (the Sheikh Said rebellion, 1925) and land reform (the Dersim rebellion, 1937–1938), and staged armed revolts that were put down with military operations.