CONQUESTS OF SONNI ALI 175 on the east, he had successfully encountered the semiindependent Fulani rulers, on whom he had imposed his suzerainty. Either at this time or later — I have been unable to ascertain the exact date — he constructed and placed upon the Niger a great fleet under the supreme command of an officer of high naval rank, corresponding to an admiral, whose headquarters were at the port of Kabara near Timbuctoo. In 1477-8-9 we find him free to devote his principal efforts to the western province and to encounter his chief enemy, the King of Mossi, who, having been driven from the Bend of the Niger, had crossed the river, and, to the terror of the unhappy professors of Aiwalatin, was making his way over the ravaged territories of Melle towards that town. The campaign which ensued in the province of Walata practically placed Melle in the hands of Sonni Ali, although in the year 1480 Aiwalatin was taken and occupied for a month by the King of Mossi. Mossi was unable to hold it, and was compelled to withdraw and to abandon the booty which he had seized. The result of the fighting would seem to have convinced Sonni Ali of the difficulty of holding and defending a frontier town in the isolated position of Aiwalatin as a part of an empire of which the river Niger was the base, for he conceived and put into partial execution the daring scheme of connecting Aiwalatin by water with Timbuctoo by means of a canal which he proposed to construct across the desert.

The fame of Sonni Ali by this time had spread beyond the limits of the Soudan. He was recognised in Northern Africa as the most powerful of the black sovereigns of the West, and he is mentioned in European annals under the name of Sonni Heli, King of Timbuctoo, whose power was acknowledged as extending to the West Atlantic coast.

It was a moment in which African affairs were beginning to be regarded with interest by European powers. The Portuguese, under Prince Henry the Navigator, had in the early part of the century begun that career of ex-