The Polish-Ukrainian War (1918-1919) was a conflict between the newly independent states of Poland and Ukraine. It arose after World War I, as both nations sought to establish control over the region of Galicia, which had a mixed population of Poles and Ukrainians. The war was marked by territorial disputes and national aspirations, leading to military confrontations. The conflict ended with the signing of the Treaty of Versailles in 1919, which favored Polish claims. Despite the war's conclusion, tensions between the two nations persisted, influencing their future relations and the broader geopolitical landscape in Eastern Europe.