Complex sentence: By October 1919, the Western Ukrainian People's Republic was defeated by Polish forces in the Polish-Ukrainian War and Eastern Galicia was annexed to Poland; the Paris Peace Conference of 1919 granted Eastern Galicia to Poland for 25 years.
Split into simpler sentences: By October 1919, the Western Ukrainian People's Republic was defeated by Polish forces in the Polish-Ukrainian War and Eastern Galicia was annexed to Poland. The Paris Peace Conference of 1919 granted Eastern Galicia to Poland for 25 years.