Kiev Offensive (1920)
The 1920 Kiev Offensive (or Kiev Expedition, Kiev Operation), considered to be the campaign that started the Polish–Soviet War proper, was an attempt by the armed forces of newly re-emerged Poland led by Józef Piłsudski, in alliance with Ukrainian exiled leader Symon Petliura, to seize the territories of modern-day Ukraine which fell under Soviet control after the October Revolution as the Ukrainian Soviet Socialist Republic. The operation led to a Soviet counter-offensive resulting in the creation of the short-lived Galician Soviet Socialist Republic. The Polish-Soviet War ended with the Peace of Riga of 1921, which settled the border between Poland and the Ukrainian Soviet Republic.