The Sahara has linked rather than divided the peoples who inhabit it and has served as an avenue for migration and conquest. Mauritania, lying next to the Atlantic coast at the western edge of the desert, received and assimilated into its complex society many waves of these migrants and conquerors. Berbers moved south to Mauritania beginning in the third century A.D., followed by Arabs in the eighth century, subjugating and assimilating Mauritania's original inhabitants. From the eighth through the fifteenth century, black kingdoms of the western Sudan, such as Ghana, Mali, and Songhai, brought their political culture from the south.

The divisive tendencies of the various groups within Mauritanian society have always worked against the development of Mauritanian unity. Both the Sanhadja Confederation, at its height from the eighth to the tenth century, and the Almoravid Empire, from the eleventh to the twelfth century, were weakened by internecine warfare, and both succumbed to further invasions from the Ghana Empire and the Almohad Empire, respectively.

The one external influence that tended to unify the country was Islam. The Islamization of Mauritania was a gradual process that spanned more than 500 years. Beginning slowly through contacts with Berber and Arab merchants engaged in the important caravan trades and rapidly advancing through the Almoravid conquests, Islamization did not take firm hold until the arrival of Yemeni Arabs in the twelfth and thirteenth centuries and was not complete until several centuries later. Gradual Islamization was accompanied by a process of arabization as well, during which the Berber masters of Mauritania lost power and became vassals of their Arab conquerors.

From the fifteenth to the nineteenth century, European contact with Mauritania was dominated by the trade for gum arabic. Rivalries among European powers enabled the Arab-Berber population, the Maures (Moors), to maintain their independence and later to exact annual payments from France, whose sovereignty over the Senegal River and the Mauritanian coast was recognized by the Congress of Vienna in 1815. Although penetration beyond the coast and the Senegal River began in earnest under Louis Faidherbe, governor of Senegal in the mid1800s , European conquest or "pacification" of the entire country did not begin until 1900. Because extensive European contact began so late in the country's history, the traditional social structure carried over into modern times with little change.

The history of French colonial policy in Mauritania is closely tied to that of the other French possessions in West Africa, particularly to that of Senegal, on which Mauritania was economically, politically, and administratively dependent until independence. The French policy of assimilation and direct rule, however, was never applied with any vigor in Mauritania, where a system that corresponded more to Britain's colonial policies of association and indirect rule developed. Colonial administrators relied extensively on Islamic religious leaders and the traditional warrior groups to maintain their rule and carry out their policies. Moreover, little attempt was made to develop the country's economy.

After World War II, Mauritania, along with the rest of French West Africa, was involved in a series of reforms of the French colonial system, culminating in independence in 1960. These reforms were part of a trend away from the official policies of assimilation and direct rule in favor of administrative decentralization and internal autonomy. Although the nationalistic fervor sweeping French West Africa at this time was largely absent in Mauritania, continuous politicking (averaging one election every eighteen months between 1946 and 1958) provided training for political leaders and awakened a political consciousness among the populace. Nevertheless, when Mauritania declared its independence in 1960, its level of political as well as economic development was, at best, embryonic.

Mauritania's postindependence history has been dominated by regional politics. Morocco and Algeria, vying for regional dominance, have continually influenced Mauritanian politics and fortunes. During the first nine years of independence, the regime of Moktar Ould Daddah was preoccupied with expansionist designs by Morocco, whose military strength constituted a perpetual threat to Mauritania's territorial integrity. This threat was intensified by the support of some of Mauritania's Maure population for unification with Morocco. In 1969, when Morocco finally recognized Mauritania's independence, the Daddah regime responded by breaking many of its extensive economic and military ties to France and establishing closer relations with Arab states, including both Morocco and Algeria.

By 1975 Mauritania had entered the military conflict over the fate of the Western Sahara. Among the inhabitants of this former Spanish territory are the Sahrawis, a group that shares ethnic ties with some of Mauritania's Maure population. The war in the Western Sahara has become a struggle by the Sahrawi liberation group, the Polisario, for national self-determination. Regionally, however, the war was and continued in 1987 to be a power struggle between Algeria, which supported the front militarily, and Morocco, which occupied the territory. Mauritania's participation in the war began with its claim to and occupation of a southern province in the Western Sahara, an action designed to prevent Morocco from occupying the entire territory. At the same time, the Daddah regime hoped to befriend Morocco by cooperating in the occupation of the Western Sahara.

Politically, from independence until the overthrow of the Daddah regime in 1978, the leadership concentrated on consolidating the power of the ruling Mauritanian People's Party and moving toward a one-party state. The regime also sought to eliminate the friction that resulted from political and social differences between the Maure and black components of the population, which could impede the attainment of national unity. Economically, the Western Sahara war, which coincided with a period of severe drought, dealt a near-fatal blow to Mauritania's development and forced the country to increasingly depend on foreign aid, mostly from conservative Arab countries.

The inability of the Daddah regime to extricate Mauritania from its economic problems and the war led to a military coup d'état in July 1978. During the next six years, the country was ruled by military regimes whose efforts to remain outside the Western Sahara conflict were impeded by the continuing war between Morocco and the Polisario, which spilled over into Mauritania's northern regions. The most durable of the military regimes during that period was led by Mohamed Khouna Ould Haidalla, who assumed power in May 1979. It survived as long as it did because Haidalla skillfully balanced the factions in his government, which included nationalists, adherents of the Western Sahara liberation cause, and proponents of close ties with Morocco. Toward the end of his regime, however, Haidalla began to arrogate authority at the expense of the other members of the ruling body, the Military Committee for National Salvation. Some of these decisions concerned highly charged political issues, such as the recognition of the Polisario's governing arm, the Sahrawi Arab Democratic Republic. The ruling committee also accused Haidalla of corruption and nepotism and decided finally, in December 1984, to depose him. This act reflected Mauritania's delicate and vulnerable regional position and the necessity for its leaders to maintain a neutral position toward the Western Sahara.