In 1825 the new Emir of Trarza, Muhammad al Habib, sought to reassert his sovereignty over the French-protected Oualo Kingdom to the south of the Senegal River by marrying the heiress to the kingdom. This action, which French authorities viewed as a hostile threat, combined with the emir's efforts to sell gum arabic to the British, brought a strong French reaction. Although the Maures were able to lay siege to Saint-Louis, a large French expeditionary force defeated the emir's forces.