The Allied invasion of Italy started when the British Eighth Army landed in the toe of Italy on 3 September 1943, in Operation Baytown. The Italian government signed the surrender the same day, believing they would be given time to make preparations against the anticipated German intervention. The Allies announced the Armistice of Cassibile on 8 September and German forces implemented plans to occupy the Italian peninsula. On 9 September, American and British forces of the US Fifth Army landed at Salerno in Operation Avalanche and more British airborne troops landed at Taranto in Operation Slapstick. German forces which had escaped from Sicily were concentrated against Avalanche, while additional forces were brought in to occupy Rome and disarm the Italian Army in central and northern Italy.