1939, World War II began by Germany invades Poland
On this day during on September 01, 1939, Nazi Germany, under Adolf Hitler, and Slovakia invades Poland, began the European phase of World War II. The first German attack of the war came against the Polish defenses at Westerplatte.

World War II or the Second World War, often abbreviated as WWII, was a global war that lasted from September 01, 1939 to September 02, 1945. It involved the vast majority of the world’s countries—including all of the great powers—forming two opposing military alliances: the Allies and the Axis powers. In a total war directly involving more than 100 million personnel from more than 30 countries.
The United Kingdom responded with an ultimatum to Germany to cease military operations, and on September 03, 1939, after the ultimatum was ignored, France and Britain declared war on Germany, followed by Australia, New Zealand, South Africa, and Canada. Germany responded by ordering U-boat warfare against Allied merchants and warships, which would later escalate into the Battle of the Atlantic.
On August 15, 1945, Japan announced its intention to surrender. Then signed the surrender document on September 02, 1945, cementing total victory in Asia for the Allies. 40,000,000–50,000,000 deaths incurred in World War II as well as the largest war, in history.
