On September 5, 1847, Muravyov was appointed the governor-general of Irkutsk and Yeniseysk (Eastern Siberia). His appointment was a subject of much controversy, as it was unusual for a person of his age (only 38 at the time) to be put in charge of such a vast territory. Contrary to the views of Karl Nesselrode, the Russian Foreign Minister, Muravyov was personally instructed by Tsar Nicholas I to press for an advantage against China. Muravyov's first action as governor-general was to put end to the embezzlement of public funds. He also mandated the study of the Russian language in schools for native Siberian and Far Eastern peoples. He pursued the exploration and settlement of the territories north of the Amur River, often utilizing the help of political exiles. Many of his actions were aimed to expand commerce in the Far Eastern region. Seeing religion as a powerful form of control over the local population, he favored the building of new Christian churches and promoted local religious beliefs such as shamanism and Buddhism.