accused were freed from prison when the state of emergency was lifted in late August 1960. Over the following months, Mandela used his free time to organise an All-In African Conference near Pietermaritzburg, Natal, in March 1961, at which 1,400 anti-apartheid delegates met, agreeing on a stay-at-home strike to mark 31 May, the day South Africa became a republic. On 29 March 1961, six years after the Treason Trial began, the judges produced a verdict of not guilty, ruling that there was insufficient evidence to convict the accused of "high treason", since they had advocated neither communism nor violent revolution; the outcome embarrassed the government. MK, the SACP, and African tour: 1961–62 Disguised as a chauffeur, Mandela travelled around the country incognito, organising the ANC's new cell structure and the planned mass stay-at-home strike. Referred to as the "Black Pimpernel" in the press—a reference to Emma Orczy's 1905 novel The Scarlet Pimpernel—a warrant for his arrest was put out by the police. Mandela held secret meetings with reporters, and after the government failed to prevent the strike, he warned them that many anti-apartheid activists would soon resort to violence through groups like the PAC's Poqo. He believed that the ANC should form an armed group to channel some of this violence in a controlled direction, convincing both ANC leader Albert Luthuli—who was morally opposed to violence—and allied activist groups of its necessity. Inspired by the actions of Fidel Castro's 26th of July Movement in the Cuban Revolution, in 1961 Mandela, Sisulu and Slovo co-founded Umkhonto we Sizwe ("Spear of the Nation", abbreviated MK). Becoming chairman of the militant group, Mandela gained ideas from literature on guerrilla warfare by Marxist militants Mao and Che Guevara as well as from the military theorist Carl von Clausewitz. Although initially declared officially separate from the ANC so as not to taint the latter's reputation, MK was later widely recognised as the party's armed wing. Most early MK members were white communists who were able to conceal Mandela in their homes; after hiding in communist Wolfie Kodesh's flat in Berea, Mandela moved to the communist-owned Liliesleaf Farm in Rivonia, there joined by Raymond Mhlaba, Slovo and Bernstein, who put together the MK constitution. Although in later life Mandela denied, for political reasons, ever being a member of the Communist Party, historical research published in 2011 strongly suggested that he had joined in the late 1950s