MINURSO

In 1975 Spain relinquished control of its former colony of Spanish Sahara following a short conflict with the Polisario, the armed movement representing many of the native Sahrawi people. In the wake of Spain's withdrawal, neighbouring Morocco and Mauritania divided and occupied the territory. In a fierce guerrilla war that saw the Polisario raid deep into Mauritania and even directly attack the capital city, the latter nation gave up any claim to Western Sahara in 1979 and withdrew. Morocco, however, chose to continue their occupation, building a massive berm stretching for hundreds of kilometres in an effort to contain the Polisario, and fighting continued until a ceasefire was agreed in 1991.

One key element of the 1991 agreement was that a UN supervised referendum would be conducted to determine the future of Western Sahara.