As I stated before, we do not even find in Songhay a regular vizier; but we find a sort of treasurer in the person of the “khatíb,” that is to say the imám who preaches before the congregation every Friday. Thus we find the great Háj Mohammed Áskía taking the whole of the money which he thought necessary for his royal pilgrimage, viz. 300,000 mithkáls, out of the royal treasury, which was in the hands of the khatíb ʿOmár[109]; but we even find, in another passage, the same khatíb authorised to liberate a princely prisoner; and, from a third passage[110], it is quite evident that the khatíb in Gágho exercised the same authority as the kádhi in Timbúktu, although we find a kádhi besides him in the capital. There appears to have been an established state prison in Songhay, namely, in a place called Kantú, the exact situation of which, however, I have not yet been able to ascertain. This prison could not fail to become of great importance as the dissensions and feuds in the royal family increased; and there appears to be no doubt that at times it was quite full of royal prisoners, and in this respect, as well as on account of the various assassinations which occurred there, fully corresponded with the character of the Tower in the middle ages. There is no doubt that polygamy, with its consequent intrigues in the harím, was the chief cause of the speedy decline of the Songhay empire from the high position it had attained under the rule of Sonni ʿAlí and Háj Mohammed Áskía. The large number of ambitious children that Áskía Dáúd, the most peaceful of the Songhay rulers, left behind him, seems especially to have contributed in a great measure to this speedy decline; but the example had been set by that ruler himself, who, having no other claims to the royal dignity than his talent and energy, revolted against his liege lord, whom he conquered and supplanted, but had himself to endure the misfortune of being persecuted, and finally dethroned in his old age, by his own son Músa.