Giarabub was the last Italian stronghold in Cyrenaica during Operation Compass, the first British offensive in North Africa in which the Tenth Army was routed and annihilated. Cut off by the Allied advance in December 1940, Castagna and his garrison of 750 Libyans (most of whom deserted during the siege) and 1,350 Italians held out for three months before being overwhelmed by the final Australian assault on 21 March 1941. The heroic resistance of the Giarabub garrison, for which Castagna and his men were commended by Erwin Rommel, was greatly exploited by Fascist propaganda, with a 1942 film (in which Castagna was played by Carlo Ninchi) and a song (La sagra di Giarabub) being made to celebrate the defenders. Castagna, who had been promoted to colonel during the siege, was wounded in the head during the final assault, captured and taken to a British hospital in Palestine and then, after recovery, to a prisoner-of-war camp in India, near Bombay, where he remained until well after the end of the war. He was only repatriated in late 1946, arriving in Italy on 23 November, and learning that both his parents had died while waiting for his return.
