1804–1830s: (The Collapse of Oyo and the Onset of the Yoruba Wars: The Fulani Jihad of 1804 Threatens the Empire, the 1817 Provincial Revolt in Ilorin Precip…

1804–1830s: (The Collapse of Oyo and the Onset of the Yoruba Wars: The Fulani Jihad of 1804 Threatens the Empire, the 1817 Provincial Revolt in Ilorin Precipitates Collapse, the Old Capital Overrun in the Early 1830s, New Oyo Retreats to the Forest, and Decades of Internecine Conflict Among Ijaye, Ibadan, the Egba, and the Ijebu — War as a Lucrative Business Producing Slaves for Illegal Export): A great many Yoruba had entered the nineteenth century united within the Oyo empire, but Oyo was a state on the brink of collapse — politically weakened by internal division and the dilution of the authority of the alafin, and economically precarious following the abolition of the slave trade. Meanwhile, the Islamic jihad which had erupted in 1804 among the Hausa and Fulani further north posed a major threat to the empire. In 1817, a provincial revolt in Ilorin, in the north of the empire, erupted with the assistance of some Fulani jihadists, precipitating not simply the collapse of Oyo but a series of wars that would engulf the Yoruba for much of the nineteenth century. The Oyo–Ilorin war reached its height in the early 1830s, when the old capital of Oyo was overrun and largely destroyed — the empire’s poor successor, New Oyo, based in the forests to the south, ceased to play an active role in Yoruba politics. The empire’s demise left a vacuum within which Ijaye, Ibadan, the Egba at Abeokuta, and the Ijebu competed violently with one another while also attempting to defend Yoruba territory from Muslim encroachments. Between the end of the 1830s and 1878, Ibadan emerged as the single most powerful Yoruba state; during a second phase from 1878 to 1893, several Yoruba states coalesced to prevent further Ibadan expansion, and it was only in 1892–1893 when the British, still based at Lagos, imposed a pax on the warring parties.