Islamic political activism has a lengthy history in Egypt. Several Islamic political groups started soon after World War I ended. The most well-known Islamic political organization is the Muslim Brotherhood (Al Ikhwan al Muslimun, also known as the Brotherhood), founded in 1928 by Hassan al Banna. After World War II, the Muslim Brotherhood acquired a reputation as a radical group prepared to use violence to achieve its religious goals. The group was implicated in several assassinations, including the murder of one prime minister. The Brotherhood had contacts with the Free Officers before the 1952 Revolution and supported most of their initial policies. The Brotherhood, however, soon came into conflict with Gamal Abdel Nasser. The government accused the Brotherhood of complicity in an alleged 1954 plot to assassinate the president and imprisoned many of the group's leaders. In the 1970s, Anwar Sadat amnestied the leaders and permitted them to resume some of their activities. But by that time, the Brotherhood was divided into at least three factions. The more militant faction was committed to a policy of political opposition to the government. A second faction advocated peaceful withdrawal from society and the creation, to the extent possible, of a separate, parallel society based upon Islamic values and law. The dominant moderate group advocated cooperation with the regime.