Zbruch River
Key buildings in Lviv were seized by Ukrainians on 31 October 1918. On 1 November, Polish residents of the city counterattacked and the Polish–Ukrainian War began. Lviv was under Polish control from 22 November. In April 1919, the Polish army of General Józef Haller arrived from France, helped drive the Ukrainian forces east past the Zbruch River and decisively contributed to the outcome of the war. The West Ukrainian People's Republic was defeated by mid-July and eastern Galicia had come under Polish administration.