As one of France's longest-held overseas territories, Algeria became a destination for hundreds of thousands of European immigrants known as "colons", and later as . However, the indigenous Muslim population remained the majority of the territory's population throughout its history. In 1835, indigenous rebels organized the Algerian resistance movement against French settlement; the rebellion was suppressed in 1903 after the "pacification campaign" by the colonial forces, who used chemical weapons, mass executions of prisoners and civilians, concentration camps and other atrocities in order to put them down. Gradually, dissatisfaction among the Muslim population due to their lack of political and economic freedom fueled calls for greater political autonomy, and eventually independence from France. Tensions between the two groups came to a head in 1954, when the first violent events began of what was later called the Algerian War, characterized by guerrilla warfare and illegal methods used by the French in order to stop the revolt. The war ended in 1962, when Algeria gained independence following the Evian agreements in March 1962 and the self-determination referendum in July 1962.