In 1136, the long-awaited imperial army, led by Lothair and the duke of Bavaria, Henry the Proud, descended the peninsula to support the three rebels. Henry, Robert, and Ranulf took a large contingent of troops to besiege the peninsular capital of the kingdom, Salerno. Roger remained in Sicily, leaving its mainland garrisons helpless under the chancellor Robert of Selby, while even the Byzantine emperor John II Comnenus sent subsidies to Lothair. Salerno surrendered, and the large army of Germans and Normans marched to the very south of Apulia. There, in June 1137, Lothair besieged and took Bari. At San Severino, after the victorious campaign, he and the pope jointly invested Ranulf as duke of Apulia in August 1137, and the emperor then retired to Germany. Roger, freed from the utmost danger, immediately disembarked in Calabria, at Tropea, with 400 knights and other troops, probably mostly Muslims. After having been welcomed by the Salernitans, he recovered ground in Campania, sacking Pozzuoli, Alife, Capua, and Avellino. Sergius was forced to acknowledge him as overlord of Naples and switch his allegiance to Anacletus. This moment marked the fall of an independent Neapolitan duchy, and thereafter the ancient city was fully integrated into the Norman realm.