198 A TROPICAL DEPENDENCY of the third vice-royalty of Bankou, which covered the country extending north-east from the river between Timbuctoo and Kagho or Gao. The eastern frontier of Bankou was again conterminous in the desert, probably about the limits of Tekadda, with that of the great vice-royalty of Dandi, which seems to have had an extension in the east equal to that of Kormina in the west. It reached from the eastern end of the southern mountains, in the neighbourhood of the province now known as Yoruba, at the back of Lagos, and after including Borgu and the country as far north as Gao on the western side of the Niger, it spread over the eastern side of the river as far as Aghadez in the northeast, and across the Haussa States to the borders of Wangara and Bornu near Lake Chad.

The exact frontiers of the vice-royalties are unknown. Presumably they did not always remain the same. But roughly speaking, if the Niger be divided into the four sections which have been indicated, that is, from the sources of the river in the west to Jenne, from Jenne to Timbuctoo, from Timbuctoo to Gao, and from Gao to a point above the junction with the Benue, which might perhaps be fixed at the Boussa rapids above Jebba, radiating lines drawn from the meeting points of those four sections to the circumference of the empire will serve to give a fairly definite impression of the political division of the outlying provinces.

The territory which remained, and which was enclosed between the river and the southern mountains in the area now known as the Bend of the Niger, was divided into the home provinces. Of these there were several of importance. Amongst them may be named Hombouri, Sansanding, and Bandouk. The old capital of the empire, and the residence always preferred by the great Askia, was Kagho, now represented only by the unimportant little town of Gao. But the true centre of political, religious, and commercial life was Timbuctoo.