Answer:
Poland.
Explanation:
The Republic of Poland then known as the Second Polish Republic was invaded by german forces from September 1, 1939 – October 6, 1939. Poland fell to german forces on September 27, 1939 after fighting bravely for 26 days. After this 140,000 polish troops were taken prisoner and Poland was divided between Germany and the Soviet Union on September 29, 1939 in accordance with the secret protol to their non-aggression pact. Poland was allied with both the United Kingdom and France who then declared war on Germany starting the Second World War.
Summary: Poland was invaded by german forces. Poland was allied with the United Kingdom and France who declared war on germany.