During the First World War Galicia saw heavy fighting between the forces of Russia and the Central Powers. The Russian forces overran most of the region in 1914 after defeating the Austro-Hungarian army in a chaotic frontier battle in the opening months of the war. They were in turn pushed out in the spring and summer of 1915 by a combined German and Austro-Hungarian offensive.
In 1918, Western Galicia became a part of the restored Republic of Poland, which absorbed the Lemko-Rusyn Republic. The local Ukrainian population briefly declared the independence of Eastern Galicia as the "West Ukrainian People's Republic". During the Polish-Soviet War the Soviets tried to establish the puppet-state of the Galician SSR in East Galicia, the government of which after couple of months was liquidated.
raison d'état