Mervyn Hiskett's Sword of Truth is a short biography of Uthman dan Fodio, the reformer and leader whose movement revolutionized Hausaland and much of today's northern Nigeria in the 19th century. Although the full history of the Sokoto Caliphate is not the main topic of Hiskett's monograph, a biography of its foundational figure is important for establishing the theological, intellectual, cultural, and political contexts of its origins. Beginning with an overview of Uthman dan Fodio's origins in a scholarly Fulani Muslim community and the larger world it was a part of, the reader is taken on a journey into the late 18th century landscape of Hausaland. Although one wonders if more recent scholarship has added more nuance to the question of "mixed Islam" and the relationship of Islamic scholars with the Habe ruling courts of the Hausa states, Hiskett's biography suggests a number of causes for the outbreak of the jihad. For instance, tensions between Fulani nomads and Hausa chiefs, the global currents of Islamic intellectual thought (though, according to Hiskett, the Shehu was not a fundamentalist or a devotee of Shaik Jibril b.Umar's iconoclasm), Hausa political corruption and abuse, arbitrary enslavement, and the Shehu's belief in his own divinely sanctioned position as a renewer of the faith. Indeed, to prepare the way for the Mahdi, the Shehu felt compelled to lead what eventually became a militant movement against the rulers of Gobir and other states for their adherence to "paganism" (or tolerance of it) and restrictions on orthodox Islam.
While the biography of Uthman dan Fodio is revealing of intellectual and religious thought in the Central Sudan during his era, Hiskett's sources are mainly from the Shehu or his family and supporters. This inherent bias does place limitations on his general narrative of the Shehu's career. The perspective of the Gobirawa dynasty, for instance, has to be gleamed from the pro-jihad sources Hiskett relies on. With the exception of the correspondence with al-Kanemi of Borno, one finds little, at least in terms of Central Sudan's Muslim intellectuals, of the regional scholars opposed to the jihad. Perhaps recent scholarship, with access to more Arabic (or Hausa) manuscripts from the pre-jihad era, can shed fuller light on the array of opinion and intellectual climate within the region and the relationship of the scholars to issues of reform, ulama-state relations, and, eventually, Uthman dan Fodio.
Nonetheless, there is much insight in Hiskett's biography and use of local Hausa sources (in Arabic and Hausa), particularly as they shed light on the transformation of the Sokoto Caliphate and the ideal state based on Sharia the Shehu and his followers sought to establish. For instance, Hiskett argues that the Shehu accepted ijma and was a devout Sufi, therefore disqualifying him from classification as a fundamentalist or Wahhabi-influenced. The gradual readoption or return to Hausa political titles in the Sokoto Caliphate, for example, or accusations of corruption and greed against political officials in it also harkened back to pre-jihad political problems of the Hausa states. While the Shehu sought to, through his brother Abdullah b. Muhammad and son, Muhammad Bello, to lay the foundations for a state closer to their Islamic ideal, the Sokoto Caliphate fell short of its initial goals. However, it further entrenched the importance and spread of Islam in the area through uniting most of the Hausa areas into a state based, in theory, on Islamic law and the prominent role of scholars. Through the encouragement of local writing in Hausa and Fulfulde on Islamic themes, the Shehu and his followers undoubtedly played a pivotal role in strengthening northern Nigeria's Islamic identity and orientation.