After the Allies captured Sicily the Italian dictator Mussolini was overthrown. The new government entered into secret negotiations to surrender to the Allies. On September 3rd the first part of Operation Avalanche the invasion of Italy was launched when British troops landed on the very tip of the boot of Italy. It was hoped that this would draw German troops to fight in that part of the Italy, but that feint failed. The British landing was however the signal the Italians needed to surrender.
The German were expecting the Italian surrender and their troops were ready to take up key Italian defensive positions. The main Allied landings took place at Salerno on September 9, 1943. The landings did not achieve tactical surprise and the Allies encountered stiff resistance. The German challenged the American advance and even launched a major counteroffensive that was almost successful. In the end however, the superior Allied air and naval support carried the day and the beachhead was secure. The Allies however, made slow progress Northward in Italy, only reaching Rome in June of the next year.