What incident increased tensions between Usman dan Fodio’s followers and Sultan Yunfa?

The breakdown in relations between Usman dan Fodio’s community and Sultan Yunfa of Gobir was triggered by a confused incident in which some of the Shaykh’s supporters forcibly freed Muslim prisoners who had been captured during a Gobir military expedition.1

While Usman had previously sought to avoid a final breach with the sultan, this event served as the catalyst for the conflict. Fearing that Degel was no longer safe, Usman followed the example of the Prophet Muhammad and carried out a hijrah (migration) to Gudu in February 1804, where he was elected imam and formally established the new caliphate.1