The 15th Army Group was activated in 1943 in Algiers, North Africa, to plan the invasion of Sicily, codenamed Operation Husky. Its main forces for this job were the U.S. Seventh Army, under Lieutenant General George Patton, and the British Eighth Army, under General Bernard Montgomery. Following the capture of Sicily, the army group became responsible for the invasion of mainland Italy for which the U.S. Seventh Army was replaced by the U.S. Fifth Army, under Lieutenant General Mark Clark. In January 1944, the army group was re-designated successively Allied forces in Italy and then Allied Central Mediterranean Force.