Reynolds, Jonathan T., 1997. "The Politics of History." Journal of Asian and African Studies 32, 1-2 (1997): 50-65,doi: https://doi.org/10.1163/15685217-90007281

The influence of religion in Nigerian politics can be traced in particular to the Islamic/political legacy of the nineteenth century Sokoto Caliphate. The legacy of this Islamic state has dramatically influenced Nigerian politics, which became particularly evident during the period of political activity in the 1950s and the subsequent events that stemmed from this activity. The Sokoto Caliphate as a model of government in northern Nigeria was in fact problematic because it only represented part of an historical tradition that was strongly affected by violence and resistance to Islamic expansion. Hence the Caliphate has been a source of tension rather than integration at the national level.

(Source: article abstract).