 Complete the following phrase:  During the campaign in Sicily, King Victor Emmanuel III of Italy arrested Prime Minister Benito Mussolini and replaced him with Pietro Badoglio, who secretly negotiated a surrender with the Allies. Germany responded by shifting several divisions to Italy, occupying Rome, and establishing a puppet state, the Italian Social Republic. The Allied invasion of mainland Italy began in September 1943. In the aftermath of Italys surrender, the Allies faced unexpectedly strong resistance from German forces under Field Marshal Albert Kesselring, who nearly defeated 