On the basis of a secret clause of the Molotov–Ribbentrop Pact, the Soviet Union invaded Poland on September 17, 1939, capturing the eastern provinces of the Second Polish Republic. The eastern provinces of interwar Poland were inhabited by an ethnically mixed population, with ethnic Poles as well as Polish Jews dominant in the cities. These lands now form the backbone of modern Western Ukraine and Western Belarus.[1][2]
The annexation of the Polish territories, which were added to Soviet Byelorussia, and the Ukrainian Soviet Socialist Republic alone, resulted in the Soviet state gaining 131,000 square kilometres (50,600 sq mi), and increasing its population by over seven million people.
- ^ Alice Teichova, Herbert Matis, Jaroslav Pátek (2000). Economic Change and the National Question in Twentieth-century Europe. Cambridge University Press. pp. 342–344. ISBN 978-0-521-63037-5.
{{cite book}}: CS1 maint: multiple names: authors list (link) - ^ Norman Davies, God's Playground (Polish edition), second tome, p.512-513.