Eastern Galicia (east of the San River), which before the outbreak of World War I was a province of the Austro-Hungarian Empire and Volyn, located to the north of Galicia, which was part of Russia is what is meant by Western Ukraine. At that time the political influences of Russia and Austria-Hungary clashed in this very region. The paper also discusses conflicts which took place in these lands between the Polish, Ukrainian and Russophile political fractions. After World War II, these lands were included in the Second Republic of Poland and the confl ict between the Soviet Union and Poland was accompanied by an increasing activity of Ukrainian nationalists. During the war they carried out a series of bloody ethnic cleansing campaigns on the Polish population, in particular in Volyn in 1943. These actions, together with the policy of the Soviet authorities immediately after the war was the reason why the Polish population left the territory. These lands were part of the Soviet Union for many years and after its collapse – Ukraine.