The Communist movement in Korea emerged as a political movement in the early 20th century. Although the movement had a minor role in pre-war politics, the division between the communist North Korea and the anti-communist South Korea came to dominate Korean political life in the post-World War II era. North Korea, officially the Democratic People's Republic of Korea, continues to be a juche socialist state under the rule of the Workers Party of Korea. In South Korea, communism remains illegal through the National Security Law. Due to end of economic aid from Soviet Union after Dissolution of the Soviet Union in 1991 and impractical ideological application of Communist economy in North Korea over years of economic slowdown in 1980s and receding during 1990s, North Korea replaced Communism with Juche ideology in its 1992 and 1998 Constitutional revision for the personal cult of Kim's family dictatorship and (albeit reluctanly) opening of North Korean market economy reform, though it still remains a centrally planned economy with complete control of the state and agriculture with collectivized farms and state-funded education and healthcare.
Alexandra Kim, a Korean who lived in Russia, is sometimes credited as the first Korean communist. She had joined the Bolsheviks in 1916. In 1917, Vladimir Lenin sent her to Siberia to mobilize Koreans there against the counter-revolutionary forces and the Allied Expeditionary Forces. In Khabarovsk Kim was in charge of external affairs at the Far-Eastern Department of the Party. There she met with Yi Dong-Wi, Kim Rip and other Korean independence fighters. Together they founded the Korean People's Socialist Party, the first Korean communist party on June 28, 1918.
The Communist Party of Korea was founded during a secret meeting in Seoul in 1925. The leaders of the party were Kim Yong-bom and Pak Hon-yong. The party became the Korean section of the Communist International at the 6th congress of the International in August–September 1928. But after only a few months as the Korean Comintern section, the perpetual feuds between rival factions that had plagued the party from its foundation led the Comintern to disband the Communist Party of Korea in December the same year. However, the party continued to exist through various party cells. Some Korean communists went into exile in China, where they participated in the early years of Communist Party of China. In the early 1930s Korean and Chinese communists began guerrilla activity against the Japanese forces.