The Treaty of Warsaw (also the Polish-Ukrainian or Petliura-Piłsudski Alliance or Agreement) of April 1920 was a military-economical alliance between the Second Polish Republic, represented by Józef Piłsudski, and the Ukrainian People’s Republic, represented by Symon Petliura, against Bolshevik Russia. The treaty was signed on 21 April 1920, with a military addendum on 24 April.

The alliance was signed during the Polish-Soviet War, just before the Polish Kiev Offensive. Piłsudski was looking for allies against the Bolsheviks and hoped to create a Międzymorze alliance; Petliura saw the alliance as the last chance to create an independent Ukraine.

The treaty had no permanent impact. The Polish-Soviet War continued and the territories in question were distributed between Russia and Poland in accordance with the 1921 Peace of Riga. Territories claimed by the Ukrainian national movement were split between the Ukrainian SSR in the east and Poland in the west (Galicia and part of Volhynia).

Every year, to celebrate the date of the pact, Centre for East European Studies organizes a scientific conference. Due to the coronavirus pandemic, the conference will not be able to take place in the traditional form. This year’s conference will take electronic form and will take place via internet connectivity. The entire conference will be available on our website.