The Emirate of Sicily was formed in 831 as part of the Aghlabid Caliphate and immediately Rome became a target for plunder. Following frequent pirate activity, which resulted in Saracen forces entering Rome and looting the Vatican in 846, the city’s defences were strengthened. A naval defence league was also set up, combining forces from the powerful cities of Amalfi, Gæta and Naples, at the request of the pope. The naval force was called to protect Rome from an imminent Saracen attack in 849. The united Italian force, led by Caesar the Brave of Naples, waited in a defensive line off the coast at Ostia and then launched an attack against the incoming Saracen forces when they neared land. In the end, the weather played the most important part in the battle as a sudden storm wrecked the majority of the Saracen ships and numerous prisoners were taken.
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