TSARIST TIMES YEARS 1918 - 1939 WORLD WAR II TO FREEDOM FILTERS 17.09.1939 – Soviet aggression against Poland The Soviet Union's invasion of Poland on 17 September 1939 came as a shock to Polish society. For several days the country had been defending itself against the German invasion. Read more 1 Reset all × 17 × Filters Reset all × 17 × Year × 1939 September— 17 1 17 22 Show (1) Cancel :