Than Tun was educated at Rangoon (Yangon) Teachers’ Training School and taught at a high school in Rangoon. Influenced at an early age by Marxist writings, in 1936 he joined in 1936 the nationalist Dobama Asi-ayone Asiayone (We“We-Burmans Association or “Our Burma Association”). Than Tun helped form the alliance between Ba Maw’s Sinyetha (Proletarian“Proletarian”) Party and the Dobama Asi-ayoneAsiayone, which resulted in the “freedom bloc” of 1940. That same year he was imprisoned by the British for sedition. When Ba Maw’s pro-Japanese government was established in 1942, Than Tun served as minister of land and agriculture. In 1943, however, he became a leader of the underground resistance movement. After the war World War II he was general secretary of the Anti-Fascist People’s Freedom League (AFPFL).
When Thakin Soe’s Red Flag Communist Party left the Burma Communist Party in early 1946, Than Tun and the majority of communists continued to cooperate with the AFPFL. In the face of increasing disagreements with the AFPFL, however, he was forced to revolt in March 1948, establishing his White Flag Party. He organized guerrilla forces in central Burma, but the government was largely successful in containing his insurgents.
In 1964 the Burmese communist movement was split by the Sino-Soviet rift. Than Tun took the side of Beijing, accusing Thakin Soe’s Red Flag Party of being Trotskyite, and he sent a number of party members to China to be trained by Chinese revolutionaries. In 1967 he carried out his own cultural revolution, purging the White Flag Party of “revisionists.” The next year Than Tun was assassinated in the Bago (Pegu) Mountains by one of his subordinates.