The recurrent crisis in the (ex-Belgian) Congo, which first exploded soon after the country's independence on 30 June 1960, was the main event in the history both of the United Nations (U.N.) and of Africa during the 1960s. Its first phase (with which this paper largely deals) opened with the mutiny of the Force publique on 5 July, the intervention of Belgian troops on 10 July, and the proclamation of Katanga's independence on 11 July; it came to an end with the suppression of Katanga's secession, tentatively in December 1961 and conclusively in January 1963. The Opération des Nations Unies au Congo (O.N.U.C.) was authorised by the Security Council on 14 July, on the independent initiative of the U.N. Secretary-General, Dag Hammarskjold, and in response to the Congo Government's appeals to the U.N. for technical and military assistance. The operation was the biggest and costliest by far in the life of the U.N.; 1 and its course was marked by political as well as financial ruin, from which the U.N. has never quite recovered. Evidence for this was furnished early. By the time the operation formally came to an end on 30 June 1964, the Congo was already in the thick of the second phase of the crisis; this phase, which began with the outbreak of rebellion in Kwilu in January 1964, was brought to an end of sorts by the Belgian-American military intervention in Stanleyville in November 1964, which produced few signs of activity by the U.N.