WWII in Photos: Invasion of Poland and Winter War

In August of 1939, Nazi Germany and the Soviet Union signed a non-aggression treaty -- one week later, Germany invaded Poland and World War II began. The first attack of the war took place on September 1, 1939, as German aircraft attacked the Polish town of Wielun, killing nearly 1,200. Five minutes later, the German battleship Schleswig-Holstein opened fire on a transit depot at Westerplatte in the Free City of Danzig. Within days, the United Kingdom and France declared war on Germany and began mobilizing their armies and preparing their civilians. On September 17, the Soviet Union invaded Poland from the east. Polish forces surrendered in early October after losing some 65,000 troops and many thousands of civilians. In November, Soviet forces invaded Finland and began a months-long battle dubbed the Winter War.