The story of Trarza begins with a tree. Across the dry plains of what is now southwest Mauritania grew stands of acacia, and from cuts in their bark seeped a hard amber resin: gum arabic. By the 18th century, this corner of the Sahara had become the world's main source of it, and the desert confederation that controlled the caravan routes carrying it to the coast grew powerful on the trade. That confederation was the Emirate of Trarza, a semi-nomadic Moorish state ruled by an emir, founded around 1640 out of the long wars between the region's old Berber inhabitants and the Arab Beni Hassan tribes who had come south. For two and a half centuries, Trarza was a force that French traders, neighboring kingdoms, and rival emirates all had to reckon with.
Trarza was one of three great emirates, alongside Brakna and Tagant, that held the northwest bank of the Senegal River from the 17th to the 19th centuries. Its rulers were Hassane, the warrior lineages who traced themselves to the Arab conquerors and sat at the top of Moorish society. Below them stood the zawiya, the scholarly clans who preserved and taught Islam and who paid the warriors a tribute, the horma, in cattle and goods in exchange for protection. It was a hierarchy held in tension, sometimes exploitative, sometimes genuinely mutual. Beneath both ranged the laboring znaga and the Haratin, and at the very bottom were enslaved people, owned by households and able to hope, at most, for freedom and a rise into the Haratin class. Trarza's wealth and power, like that of many states of its age, rested in part on the labor and trade of people who had no say in it. Their lives were as real as those of the emirs above them.
In the 17th century the French planted a trading post on the island of Saint-Louis, at the mouth of the Senegal River, and the desert merchants soon controlled the flow of goods reaching it from the interior. The most valuable of those goods was gum arabic. Europe's textile mills needed it to stiffen and finish cloth, and demand climbed steadily; in the 1830s alone, exports from Saint-Louis doubled. Trarza taxed this trade and grew fat on it. The emirate also held leverage no merchant liked: it could threaten to bypass the French entirely and sell its gum to British traders waiting up the coast at Portendick. Control of a single sticky resin had made a nomadic desert state into a power that could squeeze the commercial ambitions of a European empire.
The collision came over a marriage. A new emir, Muhammad al-Habib, struck a deal with the small Waalo kingdom on the southern bank of the river, ending his raids in exchange for the hand of its heiress. To the French, the prospect was alarming: if Trarza inherited Waalo, a single Moorish dynasty would command both banks of the Senegal and the trade that flowed between them. France answered with force. The Franco-Trarzan War of 1825 sent a large expeditionary force against Muhammad al-Habib's army and crushed it. The treaties that followed pushed French influence north of the river and, ominously for Trarza, established the principle that France would use arms, not just commerce, to keep the gum trade in its hands.
A generation later, France stopped negotiating and started building. Under the energetic governor Louis Faidherbe in the 1850s, the French strung fortified posts up the Senegal valley, determined to break African control of the interior gum trade once and for all. Trarza renewed its old alliance with Waalo and made a pact with its former rival Brakna to resist. In 1855 the combined Moorish and Waalo forces nearly seized Saint-Louis itself, but the French counterstroke was swift; at the Battle of Dioubouldou that February, the alliance was defeated and Waalo was absorbed into the French colony. By 1860 Faidherbe had forced Trarza to accept the river as the formal limit of its reach. The desert state was not yet conquered, but its horizon had been drawn for it.
Trarza's final undoing came not by cannon but by cunning. In 1901 the French administrator Xavier Coppolani launched a campaign of "peaceful penetration," exploiting the old fault line between the warrior Hassane and the scholarly zawiya. Promising the clerical clans protection and greater independence, he won over influential religious leaders, among them Shaykh Sidiya Baba, whose authority was strongest across Trarza and its neighbors. By 1904 Coppolani had brought Trarza, Brakna, and Tagant under French protection without a major battle, and the emirate that had bargained with empires was folded into a colony. Coppolani himself was killed at Tidjikja in 1905, and resistance flared in the north for years after, but Trarza's age of independent power was over. The confederation, remarkably, never quite vanished; its name lives on today in Mauritania's Trarza region, and its tribal structures persist into the present, the last echo of a state built on gum and the desert wind.
The Emirate of Trarza occupied the desert of southwest Mauritania, north of the Senegal River. Its historical heart lies around 17.50°N, 15.46°W, in the modern Trarza region between the river and the Atlantic coast. The nearest major airport is Nouakchott–Oumtounsy International (ICAO: GQNN), to the north. From the air, the defining features are the green ribbon of the Senegal River valley to the south, dividing Mauritania from Senegal, and the pale gravel plains and dunes to the north where the gum-bearing acacia once grew. The old French trading island of Saint-Louis sits at the river's mouth near the coast. Saharan dust frequently hazes the region; clearest views come in the cooler months.