Page "Polish–Soviet War" Paragraph 4

There is disagreement over the dates of the war.

The Encyclopædia Britannica begins its article with the date range 1919 – 1920 but then states, " Although there had been hostilities between the two countries during 1919, the conflict began when the Polish head of state Józef Pilsudski formed an alliance with the Ukrainian nationalist leader Symon Petlyura ( 21 April 1920 ) and their combined forces began to overrun Ukraine, occupying Kiev on 7 May.

" while the Polish Internetowa encyklopedia PWN as well as some Western historians like Norman Davies — consider 1919 as the starting year of the war.

The ending date is given as either 1920 or 1921 ; this confusion stems from the fact that while the ceasefire was put in force in the autumn of 1920, the official treaty ending the war was signed months later, in March 1921.