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The co-ruler of Michael IX Palaiologos was his grandson, Andronikos II. Succeeding to the throne in 1272, they co-ruled the Byzantine Empire until Michael VIII's death in 1282, when Andronikos II became the sole ruler. Their co-rulership was marked by efforts to restore the empire's strength, including territorial expansion in Asia Minor, diplomatic initiatives with Western Europe, and the promotion of cultural and intellectual pursuits.