Babrak Karmal befriended fellow inmate Mir Akbar Khyber, who introduced Karmal to Marxism. Karmal changed his name from Sultan Hussein to Babrak Karmal, which means "Comrade of the Workers'" in Pashtun, to disassociate himself from his bourgeois background. When he was released from prison, he continued his activities in the student union, and began to promote Marxism. Karmal spent the rest of the 1950s and the early 1960s becoming involved with Marxist organizations, of which there were at least four in Afghanistan at the time; two of the four were established by Karmal. When the 1964 Afghan Provisional Constitution, which legalised the
1979 in Afghanistan one time estimated to number 140,000. Amin is overthrown and killed in a coup backed by Soviet troops. Viktor Karpukhin carries out the taking of the presidential palace, in which two Soviet soldiers are killed. Ex-deputy prime minister Karmal, who has been in exile in Czechoslovakia, is picked as Amin's successor. The Soviets have begun a massive military airlift into Kabul, and at least two motorized divisions have crossed the Soviet-Afghan border. Babrak Karmal, whose Parcham party spearheaded the coup against Daud but later lost power to the faction led by Taraki and Amin, is considered more pro-Soviet than Amin