WORLD HISTORY

Detailed explanation-1: -German troops invaded Poland on September 1, 1939, triggering World War II. In response to German aggression, Great Britain and France declared war on Nazi Germany. Nazi Germany possessed overwhelming military superiority over Poland.

Detailed explanation-2: -In World War Two, the Polish armed forces were the fourth largest Allied forces in Europe, after those of the Soviet Union, United States, and Britain. Poles made substantial contributions to the Allied effort throughout the war, fighting on land, sea, and in the air.

Detailed explanation-3: -The Invasion of Poland: September 1st, 1939-1939 Register | findmypast.co.uk.

Detailed explanation-4: -The Soviet invasion of Poland was a military operation by the Soviet Union without a formal declaration of war. On 17 September 1939, the Soviet Union invaded Poland from the east, 16 days after Nazi Germany invaded Poland from the west.

Detailed explanation-5: -On September 1, 1939, Hitler invaded Poland from the west; two days later, France and Britain declared war on Germany, beginning World War II.