It was at this period that a learned Fulani, Othman Fodio, fell foul of the chieftain ruling over the most ancient and aristocratic of the Hausa States, Gober. The latter, fearing for his authority, ordered all the Fulani in his country to be slaughtered, with the result that Othman found himself at the head of a numerous following. Emerging successfully from the struggle, Othman preached a _jihad_, confided sacred standards to his worthiest captains and despatched them far and wide. The Hausa Chieftains were successively overthrown and replaced by Fulani, and regions unassimilated previously by the Hausas were occupied. Othman’s warriors even crossed the Niger and invaded Yorubaland, a large part of which they conquered and retained (Ilorin), the forest belt, Yoruba resistance within it, and, probably, the tsetse fly proving an insurmountable barrier to further progress southwards. Down the Niger they advanced no further than the neighbourhood of Lokoja. Othman adopted the title of _Sarikin mussulmi_, and during his life and that of his son Bello, Hausaland experienced for the first time the grip of a central, directing power. It is doubtful, however, if this change in their rulers had much effect upon the mass of the population, to whom dynastic convulsions mean very little, and it is noteworthy that the Fulani conquerors possessed sufficient statecraft to interfere but slightly with the complicated and efficient system of administration and of taxation which the Hausas had introduced. They took over the government of the towns from the Hausas, the people in many instances assisting and welcoming them. The general condition of the country remained pretty much what it had been. Moreover—and this fact is significant in connection with the arguments I shall presently adduce as regards the inspiring motive of the Fulani uprising—such of the old Hausa families who by their learning and piety had become invested with a special public sanctity were not generally molested by the conquering Fulani. Thus the Kauru, Kajura and Fatika families of Zaria, which had given birth to a long line of Mallams, were preserved in all their authority and dignity by Othman and his successors.