The siege of Syracuse in 868 was conducted by the Aghlabids against Syracuse in Sicily, then a possession of the Byzantine Empire, during the long Muslim conquest of Sicily. During the siege the Aghlabids defeated a Byzantine fleet which came to the relief of the city. Because the siege failed to take the city, the Muslims resorted to pillaging the countryside surrounding it before they retired. A decade later, the Aghlabids finally conquered the city after the siege of 877–878.