Jayin was the Alaafin who succeeded ‘Karan the cruel’. Jayin’s petty lifestyle which appeared to be dedicated much to pleasure caused the nation to look up to his kind and generous son, Olusi for hope of the glory they wished for their empire. Olusi however, fell to the kind of life built around him, and in a weak moment, was found in the embrace of one of his father’s several wives. Jayin had before then started feeling uncomfortable with Olusi’s popularity among the people. He had the son eat poison. Oyo chiefs, aware of this act of murder, arranged for Jayin’s reign to end, as did many of his predecessors’
It was during Jayin’s reign that the first king in Ijebu emerged, Agbeja Ilfe, the man sent to settle a land dispute between two quarters.