The rump kingdom of the Alafin, refounded ninety miles south of ruined Oyo-Ile, holding ceremonial primacy over a Yorubaland it no longer commanded.
Prince Atiba was crowned Alafin at Ago Oja, which was renamed Oyo; the new kingdom held only its own district while Ibadan and Ijaye wielded the real power. Its independence ended with Governor Carter's treaty signed at Oyo on 3 February 1893, which Ibadan expressly acknowledged while recognizing 'the Alafin is recognised as the King and Head of Yoruba-land'.
The monograph named for exactly this successor polity — how the Alafin's rump kingdom was rebuilt into a colonial 'empire' under indirect rule.
Johnson's Atiba chapters are the primary narrative of the refoundation at Ago Oja and the re-conferring of the Oyo titles.