August Incident (Korean: 8월 종파 사건), officially coined as the "Second Arduous March", was an attempted removal of Kim Il-sung from power by leading North Korean figures from the Soviet-Korean faction and the Yanan faction, with support from the Soviet Union and China, at the 2nd Plenary Session of the 3rd Central Committee in 1956. The attempt to remove Kim failed and the participators were arrested and later executed. Through this political struggle, Kim Il-sung quashed all opposition to him within the central party leadership.
Kim Il-sung sent out preliminary signals in late 1955 and early 1956, before the 3rd WPK Congress, that he was preparing to move against the Yanan and Soviet factions. The Twentieth Party Congress of the Soviet Communist Party was a bombshell with Nikita Khrushchev's Secret Speech denouncing Joseph Stalin and the inauguration of destalinisation. Throughout the Soviet bloc domestic Communist parties inaugurated campaigns against personality cults and the general secretaries who modelled themselves after Stalin were deposed throughout Eastern Europe.
Kim Il-sung was summoned to Moscow for six weeks in the summer of 1956 in order to receive a dressing down from Khrushchev, who wished to bring North Korea in line with the new orthodoxy. During Kim Il-sung's absence, Pak Chang-ok (the new leader of the Soviet faction after the suicide of Ho Ka-i), Choe Chang-ik, and other leading members of the Yanan faction devised a plan to attack Kim Il-sung at the next plenum of the Central Committee and criticise him for not "correcting" his leadership methods, developing a personality cult, distorting the "Leninist principle of collective leadership" his "distortions of socialist legality" (i.e. using arbitrary arrest and executions) and use other Khrushchev-era criticisms of Stalinism against Kim Il-sung's leadership.