In 1901 the French government adopted a plan of "peaceful penetration" for the administrative organization of areas then under Maure suzerainty.
The plan's author was Xavier Coppolani, a Corsican brought up in Algeria, who was sent to Mauritania as a delegate from the French government.
Coppolani set up a policy not only to divide, weaken, and pacify the Maures but also to protect them.
Although he served in Mauritania for only four years (1901–05), the French called Coppolani the father of the French colony of Mauritania, and the Maures knew him as the "Pacific Conqueror" of the territory.

During this period, there were three marabouts of great influence in Mauritania: Shaykh Sidiya Baba, whose authority was strongest in Trarza, Brakna, and Tagant; Shaykh Saad Bu, whose importance extended to Tagant and Senegal; and Shaykh Ma al Aynin, who exerted leadership in Adrar and the north, as well as in Spanish Sahara and southern Morocco.
By enlisting the support of Shaykh Sidiya and Shaykh Saad against the depredations of the warrior clans and in favor of a Pax Gallica, Coppolani was able to exploit the fundamental conflicts in Maure society.
His task was made difficult by opposition from the administration in Senegal, which saw no value in the wastelands north of the Senegal River, and by the Saint-Louis commercial companies, to whom pacification meant the end of the lucrative arms trade.
Nevertheless, by 1904 Coppolani had peacefully subdued Trarza, Brakna, and Tagant and had established French military posts across the central region of southern Mauritania.

As Faidherbe had suggested fifty years earlier, the key to the pacification of Mauritania lay in the Adrar.
There, Shaykh Ma al Aynin had begun a campaign to counteract the influence of his two rivals—the southern marabouts, Shaykh Sidiya and Shaykh Saad—and to stop the advance of the French.
Because Shaykh Ma al Aynin enjoyed military as well as moral support from Morocco, the policy of peaceful pacification gave way to active conquest.
In return for support, Shaykh Ma al Aynin recognized the Moroccan sultan's claims to sovereignty over Mauritania, which formed the basis for much of Morocco's claim to Mauritania in the late twentieth century.
In May 1905, before the French column could set out for Adrar, Coppolani was killed in Tidjikdja.

With the death of Coppolani, the tide turned in favor of Shaykh Ma al Aynin, who was able to rally many of the Maures with promises of Moroccan help.
The French government hesitated for three years while Shaykh Ma al Aynin urged a jihad to drive the French back across the Senegal.
In 1908 Colonel Henri Gouraud, who had defeated a resistance movement in the French Sudan (present-day Mali), took command of French forces as the government commissioner of the new Civil Territory of Mauritania (created in 1904), captured Atar, and received the submission of all the Adrar peoples the following year.
By 1912 all resistance in Adrar and southern Mauritania had been put down.
As a result of the conquest of Adrar, the fighting ability of the French was established, and the ascendancy of the French-supported marabouts over the warrior clans within Maure society was assured.

The fighting took a large toll on the animal herds of the nomadic Maures, who sought to replenish their herds in the traditional manner—by raiding other camps.
From 1912 to 1934, French security forces repeatedly thwarted such raids.
The last raid of the particularly troublesome and far-ranging northern nomads, the Reguibat, occurred in 1934, covered a distance of 6,000 kilometers, and netted 800 head of cattle, 270 camels, and 10 slaves.
Yet, except for minor raids and occasional attacks—Port-Etienne (present-day Nouadhibou) was attacked in 1924 and 1927—the Maures generally acquiesced to French authority.
With pacification, the French acquired responsibility for governing the vast territory of Mauritania.
In 1901 the French government adopted a plan of "peaceful penetration" for the administrative organization of areas then under Maure suzerainty. The plan's author was Xavier Coppolani, a Corsican brought up in Algeria, who was sent to Mauritania as a delegate from the French government. Coppolani set up a policy not only to divide, weaken, and pacify the Maures but also to protect them. Although he served in Mauritania for only four years (1901–05), the French called Coppolani the father of the French colony of Mauritania, and the Maures knew him as the "Pacific Conqueror" of the territory.
During this period, there were three marabouts of great influence in Mauritania: Shaykh Sidiya Baba, whose authority was strongest in Trarza, Brakna, and Tagant; Shaykh Saad Bu, whose importance extended to Tagant and Senegal; and Shaykh Ma al Aynin, who exerted leadership in Adrar and the north, as well as in Spanish Sahara and southern Morocco. By enlisting the support of Shaykh Sidiya and Shaykh Saad against the depredations of the warrior clans and in favor of a Pax Gallica, Coppolani was able to exploit the fundamental conflicts in Maure society. His task was made difficult by opposition from the administration in Senegal, which saw no value in the wastelands north of the Senegal River, and by the Saint-Louis commercial companies, to whom pacification meant the end of the lucrative arms trade. Nevertheless, by 1904 Coppolani had peacefully subdued Trarza, Brakna, and Tagant and had established French military posts across the central region of southern Mauritania.
As Faidherbe had suggested fifty years earlier, the key to the pacification of Mauritania lay in the Adrar. There, Shaykh Ma al Aynin had begun a campaign to counteract the influence of his two rivals—the southern marabouts, Shaykh Sidiya and Shaykh Saad—and to stop the advance of the French. Because Shaykh Ma al Aynin enjoyed military as well as moral support from Morocco, the policy of peaceful pacification gave way to active conquest. In return for support, Shaykh Ma al Aynin recognized the Moroccan sultan's claims to sovereignty over Mauritania, which formed the basis for much of Morocco's claim to Mauritania in the late twentieth century. In May 1905, before the French column could set out for Adrar, Coppolani was killed in Tidjikdja.
With the death of Coppolani, the tide turned in favor of Shaykh Ma al Aynin, who was able to rally many of the Maures with promises of Moroccan help. The French government hesitated for three years while Shaykh Ma al Aynin urged a jihad to drive the French back across the Senegal. In 1908 Colonel Henri Gouraud, who had defeated a resistance movement in the French Sudan (present-day Mali), took command of French forces as the government commissioner of the new Civil Territory of Mauritania (created in 1904), captured Atar, and received the submission of all the Adrar peoples the following year. By 1912 all resistance in Adrar and southern Mauritania had been put down. As a result of the conquest of Adrar, the fighting ability of the French was established, and the ascendancy of the French-supported marabouts over the warrior clans within Maure society was assured.
The fighting took a large toll on the animal herds of the nomadic Maures, who sought to replenish their herds in the traditional manner—by raiding other camps. From 1912 to 1934, French security forces repeatedly thwarted such raids. The last raid of the particularly troublesome and far-ranging northern nomads, the Reguibat, occurred in 1934, covered a distance of 6,000 kilometers, and netted 800 head of cattle, 270 camels, and 10 slaves. Yet, except for minor raids and occasional attacks—Port-Etienne (present-day Nouadhibou) was attacked in 1924 and 1927—the Maures generally acquiesced to French authority. With pacification, the French acquired responsibility for governing the vast territory of Mauritania.
Colonial Mauritania