During the era of the People 's Republic of Poland , the Polish communist authorities colluded with the Soviet Union to censor information about the Soviet invasion of Poland in 1939 and repressions carried out against the Polish population during the period of Soviet occupation from 1939 - 1941 , as well as subsequent repressions following the Soviet takeover of Poland in 1944-5 , in particular - denying Soviet culpability for the Katyn massacre of 1940 . After the fall of the communist governments in Central and Eastern Europe in 1989 , the new authorities in Poland officially endorsed a project to create a number of monuments and memorials commemorating those events
Katyn massacre
Katyn massacre
Monument to the Fallen and Murdered in the East