Battle of Isly

In 1844 France was fighting to crush Abd el-Kader, the Algerian leader who had taken refuge across the border in Morocco with the sultan's support. After clashes near Oujda, the sultan's son Moulay Muhammad gathered a big army of horsemen near the Isly river. On 14 August Marshal Bugeaud, with far fewer men, marched out in a formation known as the boar's head, a wedge of squares with the cavalry and guns inside. The Moroccan horsemen charged and failed to break the squares, and the French counterattack overran their camp. The defeat, together with French naval bombardments of Tangier and Mogador, led Morocco to withdraw its support for Abd el-Kader.

French accounts dominate the record, and they put Moroccan strength very high and French losses very low, while Moroccan chronicles of the time are brief, so the scale of the victory is hard to judge. Many historians see the defeat as the moment European military and naval power was shown to be decisive against the sultanate, pushing the Moroccan court toward reform and, in time, heavy European influence, though that reading is debated.