Introduction to the Decembrist tombstone: In December 1825 (Russian calendar), an uprising against the Tsarist autocratic system occurred in Russian history. In 1821, a group of aristocratic officers with democratic ideas established a revolutionary organization, planned an uprising, and advocated the establishment of a republic or a constitutional monarchy. On December 14, 1825, taking advantage of the sudden death of Tsar Alexander I, they launched uprisings in Petersburg and Ukraine, but failed. Later, more than 500 people were tried, five leaders were executed, and more than 100 people were exiled to Siberia. They were called "December Party". They have made important contributions to the development of Siberia and are loved by the people of Irkutsk.