The Western Sahara War was an armed struggle between the Sahrawi Polisario Front and Morocco between 1975 and 1991, being the first and most significant phase of the Polisario-Morocco conflict. The conflict erupted after the withdrawal of Spain from the Spanish Sahara in accordance with the Madrid Accords, by which it gave administrative control of the territory to Morocco and Mauritania, but not the sovereignity. The Polisario Front, desiring to establish an independent state in the territory, successively fought Mauritania and Morocco. In 1979, Mauritania withdrew from the conflict after signing a peace treaty with the Polisario, and a cease-fire agreement was reached with Morocco in 1991. Today most of the territory of Western Sahara is under Moroccan control.

In 1884 Spain claimed a protectorate over the coast from Cape Bojador to Cap Blanc. Later, the Spanish extended their area of control. In 1958 Spain joined the previously separate districts of Saguia el-Hamra (in the north) and Río de Oro (in the south) to form the province of Spanish Sahara.

Coordinates: 25°N 13°W / 25°N 13°W / 25; -13

Western Sahara (US ⁱ/ˌwɛstərn səˈhærə/, UK /ˌwɛstən səˈhɑrə/; Arabic: الصحراء الغربية‎ Aṣ-Ṣaḥrā’ al-Gharbīyah; Spanish: Sahara Occidental), is a disputed territory in North Africa, bordered by Morocco to the north, Algeria to the northeast, Mauritania to the east and south, and the Atlantic Ocean to the west. Its surface area amounts to 266,000 square kilometres (103,000 sq mi). It is one of the most sparsely populated territories in the world, mainly consisting of desert flatlands. The population is estimated at just over 500,000, many of whom live in El Aaiún (also called Laâyoune), the largest city in Western Sahara.

A colony of Spain since the late 19th century, the Western Sahara has been on the United Nations list of non-self-governing territories since 1963. In 1965, the UN General Assembly adopted its first resolution on Western Sahara, asking Spain to decolonise the territory. One year later, a new resolution was passed by the General Assembly requesting that a referendum be held by Spain on self-determination. In 1975, Spain relinquished the administrative control of the territory to a joint administration by Morocco, which had formally claimed the territory since 1957, and Mauritania. A war erupted between those countries and the Sahrawi national liberation movement Polisario Front, which proclaimed the Sahrawi Arab Democratic Republic (SADR) (exiled government in Tindouf, Algeria). Mauritania withdrew in 1979 and Morocco eventually secured effective control of most of the territory, including all the major cities and natural resources.

The Sahara (Arabic: الصحراء الكبرى‎, Aṣ-Ṣaḥrā´ al-Kubrā, "The Great Desert") is the world's largest hot desert and second largest desert, after Antarctica. At over 9,400,000 square kilometres (3,600,000 sq mi), it covers most of Northern Africa, making it almost as large as China or the United States. The Sahara stretches from the Red Sea, including parts of the Mediterranean coasts, to the outskirts of the Atlantic Ocean. To the south, it is delimited by the Sahel, a belt of semi-arid tropical savanna that composes the northern region of central and western Sub-Saharan Africa.

Some of the sand dunes can reach 180 metres (590 ft) in height. The name comes from the Arabic word for desert: (صَحراء ṣaḥrāʾ [sˤɑħrɑːʔ] ( listen)).

The Sahara's boundaries are the Atlantic Ocean on the west, the Atlas Mountains and the Mediterranean Sea on the north, the Red Sea on the east, and the Sudan (region) and the valley of the Niger River on the south. The Sahara is divided into western Sahara, the central Ahaggar Mountains, the Tibesti Mountains, the Air Mountains (a region of desert mountains and high plateaus), Ténéré desert and the Libyan desert (the most arid region). The highest peak in the Sahara is Emi Koussi (3,415 m/11,204 ft) in the Tibesti Mountains in northern Chad.