Answer:
Germany Declares war on Poland in September 1, 1939
Step-by-step explanation:
World War II officially started between France, England, and her colonies on September 1, 1939. Neville Chamberlain gave Adolf Hitler a large portion of Czechoslovakia in exchange for his word to not continue to expand the 3rd Reich. Hitler, being a ruthless dictator, did not keep to his word and marched troops, tanks, and equipment into Poland in 1939, forcing England and her ally, France, to officially declare war on Nazi Germany.
Hope this helps
H.M.