Gaulle, a new constitution (October 13, 1946) established the Fourth Republic under a parliamentary form of government, controlled by a series of coalitions. The mixed nature of the coalitions and a consequent lack of agreement on measures for dealing with colonial wars in Indochina and Algeria caused successive cabinet crises and changes of government. The war in Indochina ended with French defeat and withdrawal in 1954. Algeria was no mere colony. With over a million European residents in Algeria (the pieds-noir), France refused to grant it independence, until a bloody colonial war (the Algerian War of Independence) had turned into a French political and civil crisis; Algeria was given its independence in 1962, unleashing a massive wave of immigration from the former colony back to France. The threat of a coup d'état in May 1958 by French army units and French settlers opposed to concessions in the face of Arab nationalist insurrection led to the fall of the French government and a presidential invitation to de Gaulle to form an emergency government to forestall the threat of civil war. Swiftly replacing the existing constitution with one strengthening the powers of the presidency, he became the elected president in December of that year, inaugurating France's Fifth Republic. In July 1961 when Tunisia imposed a blockade on the French naval base at Bizerte, hoping to force its evacuation the crisis culminated in a three-day battle between French and Tunisian forces that left some 630 Tunisians and 24 French dead, and eventually led to France ceding the city and naval base to Tunisia in 1963. In 1965, in an occasion marking the first time in the 20th century that the people of France went to the polls to elect a president by direct ballot, de Gaulle won re-election with a 55% share of the vote, defeating François Mitterrand. Meanwhile, the Algerian War went on raging, with de Gaulle progressively adopting a stance favouring Algeria's independence. This was interpreted by his supporters in 1958 as a form of treason, and part of them, who organized themselves in the OAS terrorist group, rebelled against him during the Algiers putsch of 1961. But De Gaulle managed to put an end to the war by negotiating the Evian Agreements of March 1962 with the FLN. In the end of the 1960s, however, French society grew tired of the heavy-handed, patriarchal Gaullist approach, and of the incompatibilities between