The resultant South Korean government promulgated a national political constitution on 17 July 1948, and elected Syngman Rhee as President on 20 July 1948. The Republic of Korea (South Korea) was established on 15 August 1948. In the Russian Korean Zone of Occupation, the Soviet Union established a Communist North Korean government led by Kim Il-sung. President Rhee's régime excluded communists and leftists from southern politics. Disenfranchised, they headed for the hills, to prepare for guerrilla war against the US-sponsored ROK Government.