After some preliminary engagements at Campo Baccano and at Trevi, the Saracens were driven to their stronghold on the Garigliano. There, at the Battle of Garigliano, the allies proceeded to lay siege to them for three months, at the end of which the Saracens burnt their houses and attempted to burst out of the encirclement. With John leading the way, all were eventually caught and killed, achieving a great victory and removing the ongoing Saracen threat on the Italian mainland. John then confirmed the granting of Traetto to the Duke of Gaeta, as a reward for abandoning his Saracen allies.