In 1817 and 1818, he was a
Freemason, a member and a ritual-keeper of the "Three Virtues" Lodge. He was one of the founders of pre-Decembrist secret societies
Union of Salvation and
Union of Welfare, and a director of the Decembrist Southern Society. He was the coordinator of correspondence between the Southern Society and the pro-
Polish Society of United Slavs. Muravyov-Apostol was the author of the Decembrists
Сatechesis and a very articulate supporter of establishing a
republic and abolishing
serfdom in Russia. In 1825, he led the
uprising of the Chernigov regiment. He was arrested on then freed by his fellow officers. He led an insurgency against government forces on , when he was critically wounded by a
canister shot. According to the legend, his wounds prevented him from staying in the saddle. So he ordered to be fastened to his horse by ropes so as to lead the desperate cavalry attack on the government artillery battery. The attack was unsuccessful and he was captured. He was delivered to Saint Petersburg and was one of the five Decembrists sentenced to
quartering, but later this sentence was replaced with
hanging. He was executed along with the other 4 in
Peter and Paul Fortress on . He was interred with the other four in a secret grave on
Goloday Island, though some conspiracy theorists believed that the men were not hanged but put on the island to starve. In the Soviet era, the island was renamed "Decembrists' Island" in memory of the executed men. ==See also==