with reference to the war mentioned previously, which year did the war first begin?
1 September 1939
World War II
World War II is generally considered to have begun on 1 September 1939, with the invasion of Poland by Germany and subsequent declarations of war on Germany by France and the United Kingdom. 
what is montana-class battleship? A class of battleships can you specifically name a few battleships that come under that class? USS "Ohio", USS "Maine", USS "New Hampshire" which company built this class? The United States Navy which wars did such class of warships participated in? World War II what were the typical armaments found in such a class? An increase in the number of primary guns and more potent secondary guns for use against enemy surface ships and aircraft.
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World War II [SEP] Introduction
Key setbacks in 1943—including a series of German defeats on the Eastern Front, the Allied invasions of Sicily and Italy, and Allied offensives in the Pacific—cost the Axis its initiative and forced it into strategic retreat on all fronts. In 1944, the Western Allies invaded German-occupied France, while the Soviet Union regained its territorial losses and turned towards Germany and its allies. During 1944 and 1945, Japan suffered reversals in mainland Asia, while the Allies crippled the Japanese Navy and captured key Western Pacific islands.