120 A TROPICAL DEPENDENCY Under Sakora the territories of Melle were as much extended in the east as they had been by the conquest of Ghana in the west, for he conquered Gago or Kaougha, the capital of Songhay, of which the site was the present town of Gao. This town was, at the beginning of the fourteenth century, the centre of a rich and important territory shaken for the moment by internal convulsions, and therefore open to conquest by a powerful neighbour.

In the twelfth century it was described by El Idrisi as a "populous, unwalled, commercial and industrial town, in which were to be found the produce of all arts and trades necessary for the use of its inhabitants." Ibn Said, in the thirteenth century, speaks of it also with respect. It was throughout its history celebrated for the great quantity of gold with which its markets abounded ; it will be remembered that this peculiarity was noted by El Bekri.

The Mohammedanism of Songhay, having presumably come to it by the eastern and not by the western road, dated from an earlier period than that of Melle and Ghana. The first of the Songhay kings to accept Islam was Za-Kosoi, whose conversion took place in 1009. The early kings of Songhay were all known by the title of " Za," which was afterwards changed to Sonni, and at a later period still to Askia or Iskia. The " Zas " were still reigning when Songhay was conquered in the early years of the fourteenth century.

Mansa Musa, the next great king of Melle, completed the conquests made by Sakora, and Songhay remained subject to Melle until about the year 1356. Although m its state of unwalled prosperity it fell a comparatively easy prey to the military strength of Melle, it is probable that Songhay regarded itself even at that period as possessing a higher civilisation than that of its conquerors. In including it within the territories of the Mellestine and causing its princes to be brought up at his own courts, the Sultan of Melle unconsciously played the part of one who takes to his hearth a slave destined eventually to