What He Wrote, and Who He Wrote It For

He wrote in three languages and for three audiences. Arabic carried the legal and theological work addressed to scholars, including Bayan Wujub al-Hijra ala al-Ibad, which sets out the obligation to withdraw from an unjust ruler, and Ihya al-Sunna wa Ikhmad al-Bid'a, which distinguishes practice he regarded as authentic from practice he regarded as innovation.

Fulfulde and Hausa verse carried the same arguments to people who did not read Arabic, and that verse was meant to be recited and memorised, which is how doctrine actually moved in the region. The output is enormous and much of it has never been printed. Two strands matter beyond the political history. The first is Sufi: he belonged to the Qadiriyya, wrote on the spiritual path, and reported visionary experiences, so the movement cannot be read as a purely legalist purge. The second is the education of women. He argued that a man who leaves his wives and daughters ignorant of their religious obligations wrongs them, and against husbands who prevented them from learning. That position, unusual in its context, is the ground his daughter Nana Asma'u built the Yan Taru teaching network on, and it is the reason the caliphate produced a substantial body of writing by a woman.