The Kisra legend is a migration story shared by a number of political and ethnic groups in modern Nigeria, Benin, and Cameroon, primarily the Borgu kingdom and the people of the Benue River valley. The migration legend depicts the arrival of a large military force in what is currently Northern Nigeria around the 7th Century AD. The Borgu kingdom claimed direct descent from the leader of this migration and a number of other polities recognize the migration through ceremony and formal regalia. There are a number of different versions of the legend with Kisra sometimes being depicted as a religious and military rival to Muhammad near Mecca around the time that Islam was founded and sometimes as the remnant forces of a Persian king defeated in Egypt. The legend was a key piece of evidence in a number of Hamitic historical theories which argued that the political development of societies in sub-Saharan Africa was the result of contacts with societies from the Middle East (namely Egypt, Rome, and the Byzantine Empire).
The legend is shared by many different political and ethnic entities throughout what is currently northern Nigeria and has provided important linkages between these communities. Although the different versions share a similar depiction of a large migration into the area along the Niger river in around the 7th Century. Two of the most prominent versions of the story depict Kisra as a challenger to Muhammad on the Arabian peninsula or as a Persian ruler who suffered a military defeat in Egypt. However, in some versions Kisra is not an individual person but a generalized title for the leader of the migration as it moved across Africa. Versions also differ on other aspects of the story, namely whether or not Kisra himself founded any of the royal lines and the specifics of his death or magical disappearance.
In the most prominent version of the story in the Borgu kingdom, Kisra is depicted as an early political and religious challenger to Muhammad in the area around Mecca. In this version, Kisra was a prominent leader and possessed a number of magical powers. However, during his rule, a seer foresaw that his power would eventually be undermined by a child born within the city who would have divine powers. To prevent this challenge, Kisra exiled all the men of his city on the date that the seer had predicted the baby to be conceived; however, the husband of Aminatu, Kisra's daughter, remained in the city and a son was conceived, Muhammad. As Muhammad grew, he began trying to convert Kisra to Islam, but the ruler resisted. Eventually, this resulted in open warfare between Muhammad and Kisra over religious issues and Kisra won the initial conflict. However, as Muhammad fled to a baobab tree he was provided divine assistance for his escape and to reorganize his forces. Seeing that the tables had turned, Kisra and his followers left the Arabian peninsula, eventually reaching the Niger river. Kisra's party visited many of the villages in the area before eventually founding the Borgu kingdom. In some versions of the legend, Kisra's oldest son Woru (or sometimes Kisra himself) founded the city of Bussa, which would become the capital of Borgu. Kisra's younger sons founded Nikki, founded by Shabi, and Illo, founded by Bio. In later versions, this order of foundation of the main cities of the Borgu kingdom is changed. The legend became crucial in the Borgu kingdom in uniting the different cities, legitimizing the ruling dynasty (the Wasangari), and providing an ideological distinction between Borgu and the Islamic states in the area.