Kisra was a mythic hero.
He arose in Mecca, preaching a new religion, and was driven from there with his followers by the Muslims. In other accounts, Kisra, the head of a tiny clan, caused a great stir by refusing to accept the reforms of the Prophet or to be converted to Islam. There was a struggle, and he was defeated. With his followers he was forced to cross to Africa and eventually to traverse the continent until he came to the Niger River. Tradition connects the Yoruba emigration to that of Kisra. The Yoruba may have been a part of the clan of which Kisra was the head; they unsuccessfully attempted to persuade Kisra to lead them, and eventually went without him. Kisra's followers at last crossed the Niger at Illo, and the river was immediately afterward widened to its present size by a miracle. It is not certain who caused the miracle. It may have been Kisra, who, being pursued by Muslims, thus brought pursuit to an end, or it may have been the Muslims, who thereby prevented the unbelievers from ever returning to Mecca. When the river was crossed, Kisra expressed his intention of finally settling down. The people, who had so long held together, now broke up. Minor chiefs, perhaps the younger brothers of Kisra, founded the towns of Nikki and Illo. They still looked, however, to Kisra as their leader, both spiritual and temporal. He himself set up the kingdom of Busa, and his semipriestly status has been handed down to every succeeding king of Busa and is largely responsible for the sphere of their influence.