Giuseppe Castellano Giuseppe Castellano ( Prato , September 12 , 1893 – Porretta Terme , July 31 , 1977 ) was an Italian general who negotiated the Armistice between Italy and Allied armed forces on September 8 , 1943 . Biography . Military career . Of Sicilian descent but born in Prato he was the son of a military man . His career in the Army was rapid and brilliant . In the First World War he was Captain of Artillery . In 1941 , he was promoted to Brigadier General during the Invasion of Yugoslavia , and was at that time , the youngest general in Italy . In 1942 he was called to the Army General Staff and the following year , to the High Command and collaborated as personal aide with General Vittorio Ambrosio . He was a close friend of Benito Mussolini ' s son - in - law Galeazzo Ciano , who was the Italian Minister of Foreign Affairs . Ciano was involved in ousting Mussolini in July 1943 after the Allied invasion of Sicily . Castellano sided with Ciano and had a prominent role in the events that led up to the fall of the fascist regime . He organised the arrest of Mussolini . Armistice with the Allied armed forces . The new Prime Minister , Pietro Badoglio , sent Castellano to Lisbon in order to contact Allied diplomats to set the conditions for the surrender of Italy . He ordered Castellano to insist that any surrender of Italy was subject to a landing of Allied troops on the Italian mainland ( the Allies at this point were holding Sicily and some minor islands ) . Badoglio also dared to ask for access to Allied military plans , which was not accepted . After complicated negotiations the government and king accepted the conditions for the armistice . On September 3 , 1943 , Castellano , in lieu of Badoglio , and General Walter Bedell Smith , in place of General Dwight D . Eisenhower , signed the armistice agreement in the town of Cassibile , near Syracuse , in Sicily . The agreement was not announced until September 8 , when Badoglio addressed the nation during a radio broadcast . Intervention in post - war Sicilian politics . After the armistice Castellano emerged as Sicily ’ s military commander . He had been given powers to hold talks to resolve the separatist threat to Italian unity . He became convinced that the Mafia was the strongest political and social force on Sicily to be reckoned with . He started to establish cordial relations with Mafia leaders . The general believed that law and order could be restored if " the system formerly employed by the old and respected Maf ( f ) ia should return to the Sicilian scene . " Castellano made contacts with Mafia leaders and met with them several times . He gained the cooperation of Mafia boss Calogero Vizzini , who had supported separatism but was now prepared for a change in the island ’ s political situation . Together with Vizzini , he approached Trapani politician Virgilio Nasi to offer him the leadership of a movement for Sicilian autonomy with the support of the Mafia . The plan was to stage Nasi as a candidate for High Commissioner for Sicily to oppose the favourite , the Christian Democrat Salvatore Aldisio . Castellano ’ s initiative weakened the Sicilian Independence Movement ( Movimento Indipendentista Siciliano , MIS ) of Andrea Finocchiaro Aprile . The Mafia , however , became a force of order and stability on the island and prevented a separatist overthrow by stifling extremist elements in the movement . The seeds were planted from which the Mafia would tremendously benefit in the decades to come . Retirement and death . He wrote a number of books about his experiences during the War : " Come firmai l ' armistizio di Cassabile " ( How I signed the armistice in Cassabile ) , published by Mondadori in 1945 ; " La guerra continua " ( The continuous war ) ; and " Roma Kaputt " . In 1947 , he retired from the Army and became the director of a chain of hotels and thermal baths for some years . He died in Porretta Terme on July 31 , 1977 .