Myth: It started in 1939
Most history books tell us that World War II began on September 1, 1939, when the Nazis invaded Poland. Hell, some Americans probably think the war started on December 7, 1941, when Japan bombed Pearl Harbor.
However, many historians suggest earlier starting points including the Soviet-Japanese fighting in Mongolia in May 1939, the beginning of the Second Sino-Japanese War in 1937, the Italian invasion of Abyssinia in 1935, and even the Japanese invasion of Manchuria in 1931.
But, a war’s victors are always the ones who later write its history. And so the world powers on the winning side of World War II ultimately pegged the start of the war as the moment when they got involved.