the Louvre Museum in Paris, France. Despite the Almoravid domination of Spain in the eleventh and twelfth centuries, there seems to be little evidence of contact during that time between Mauritania and Europe. The inhospitable coastline of Mauritania continued to deter voyagers until the Portuguese began their African explorations in the fifteenth century. Lured by legends of vast wealth in interior kingdoms, the Portuguese established a trading fort at Arguin, southeast of Cap Blanc (present-day Ras Nouadhibou), in 1455. The king of Portugal also maintained a commercial agent at Ouadane in the Adrar in an attempt to divert gold traveling north by caravan. Having only slight success in their quest for gold, the Portuguese quickly adapted to dealing in slaves. In the mid-fifteenth century, as many as 1,000 slaves per year were exported from Arguin to Europe and to the Portuguese sugar plantations on the island of São Tomé in the Gulf of Guinea. With the merger of the Portuguese and Spanish crowns in 1580, the Spaniards became the dominant influence along the coast. In 1638, however, they were replaced by the Dutch, who were the first to begin exploiting the gum arabic trade. Produced by the acacia trees of Trarza and Brakna and used in textile pattern printing, this gum arabic was considered superior to that previously obtained in Arabia. By 1678 the French had driven out the Dutch and established a permanent settlement at Saint Louis at the mouth of the Senegal River, where the French Company of the Senegal River (Compagnie Française du Sénégal) had been trading for more than fifty years. The Moors, with whom the Europeans were trading, considered the constant rivalries between European powers a sign of weakness, and they quickly learned the benefits of playing one power against the other. For example, they agreed simultaneously to give monopolies to the French and the Dutch. The Maures also took advantage of the Europeans whenever possible, so that when the French negotiated with the amir of Trarza to secure a monopoly on the gum Arabic trade, the amir in exchange demanded a considerable number of gifts. Thus began the custom, an annual payment expected by the Maures for doing business with a government or a company. By 1763 the British had expelled France from the West African coast, and France recovered control only when the Congress of Vienna in 1815 recognized French sovereignty over the