(after 1924, Partai Kommunis Indonesia) Indonesian Communist Party. Formed in 1920, the PKI was active in trade-union activities, but Dutch repression and the abortive communist uprisings in Banten and West Sumatra in 1926–27 led to its eclipse until 1945. During the 1950s, the PKI became one of the largest communist parties outside China and the Soviet Union, winning 20% of the vote in the 1955 general elections. Rivalry with the army and communist-inspired actions against Muslim landlords in Java provoked the military to move against it after the abortive left-wing coup attempt of 1965. Up to one million PKI members were killed and the party was all but wiped out.