Operation Avalanche Operation Avalanche Operation Avalanche was the codename for the Allied landings near the port of Salerno, executed on 9 September 1943, part of the Allied invasion of Italy. The Italians withdrew from the war the day before the invasion, but the Allies landed in an area defended by German troops. Planned under the name "Top Hat", it was supported by the deception plan Operation Boardman. The landings were carried out by the US Fifth Army, under American General Mark W. Clark. It comprised the U.S. VI Corps, the British X Corps and the US 82nd Airborne Division, a total of
World War II by country Union. Ukraine was part of the Soviet Union during World War II. So see this article's section on the Soviet Union. The United Kingdom was one of the original Allies, entering the war in 1939 to honour its guarantees to Poland. After the fall of France, the United Kingdom was the only Allied nation left in Europe until the invasion of Greece. It remained the only one of the Big Three in the war until 1941 when the Soviet Union was invaded. The United Kingdom was heavily engaged in the Western European, Atlantic, Mediterranean, African and South East Asian theatres,