Era −1 — Pre-1900: jihad, civil war and monetary collapse — Jigawa State

1805 — Sokoto jihad: Sambo dan Salihu founds the Hadejia Emirate; the Hausa town of Biram is overrun, the Sarkin Biram lineage deposed.
1818 — Dan Tunku founds the Kazaure Emirate; resistance from Hausa pagans of the Falgore forest crushed.
1848–1863 — Hadejia Wars / Buhari's Revolt. Buhari dan Sambo of Hadejia repudiates Sokoto, raids Kano caravans for fifteen years. Inter-Caliphate war kills an estimated 20,000 across Hadejia, Kano, Katagum and Misau. Buhari killed at Garin Gabas, 1863. The floodplain depopulates; Auyo and Garki never recover their pre-war population.
1855–1898 — Slave-raiding economy. Hadejia and Gumel raid the Manga and Bade villages of the present-day Yobe border for slaves traded to Kano and Bornu.
1880–1900 — Cowrie collapse. The fiscal base of the Hadejia, Kazaure, Gumel and Dutse Beit-el-mals collapses as British silver displaces the cowrie. See How the currency fell before the flag.