When Gamal Abdel Nasser seized power in Egypt in 1952, many Iraqi military officers were inspired by his anti-Western, left-wing policies. Calling themselves the Free Officers (a name that had been used by revolutionary Egyptian army officers), they were led by a core organization of fourteen officers. On July 14, 1958, the Free Officers took over the government in a well-planned coup. They killed Prime Minister al-Said, King Faisal II, and most leading members of the royal house. The officers proclaimed a republic and issued a provisional constitution. General Abdul Karim Kassim formed a revolutionary council and named himself commander of the national forces.
The Kassim regime denounced the Western nations and withdrew from the Baghdad Pact. The dictatorial regime tried scores of high officials and senior officers from the previous government in a special court. All democratic institutions were abolished. Conflicts among the revolutionary officers soon appeared, however, and Iraqi relations with Egypt and Syria deteriorated.
In 1959 Kassim was wounded in an attempted assassination. Afterward he spent most of his time in seclusion. In 1961 Kassim suddenly resurrected Iraqi claims of sovereignty over neighboring Kuwait. This brought him into conflict with Britain, as well as neighboring Arab countries. The next year, the government tried to crack down on Kurdish separatists led by Musafa al-Barzani. However, the military campaign failed, and a long guerrilla war began.
By 1963 Kassim's most determined opponents were the active members of the Arab Socialist Baath (or "resurrection") Party. It championed a secular ideology that included a mixture of socialism, pan-Arab unity, economic development, and opposition to European imperialism. Imported from Syria to Iraq in 1949, the party was strictly organized in cells at the local level, and it emphasized strict obedience to party leaders.
Although the Baath Party initially supported Kassim, its leaders soon disagreed with his policies and attempted to assassinate him in 1959. Even after Baath leaders went into exile in neighboring countries, the party continued to grow. By 1963 it had 850 active members and about 15,000 sympathizers.