Wiesenthal was born on 31 December 1908, in Buczacz (Buchach), Kingdom of Galicia and Lodomeria, then part of Austria-Hungary, now Ternopil Oblast, in Ukraine. His father, Asher Wiesenthal, was a wholesaler who had emigrated from the Russian Empire in 1905 to escape the frequent pogroms against Jews. A reservist in the Austro-Hungarian Army, Asher was called to active duty in 1914 at the start of World War I. He died in combat on the Eastern Front in 1915. The remainder of the family—Simon, his younger brother Hillel, and his mother Rosa—fled to Vienna as the Russian army took control of Galicia. The two boys attended a German-language Jewish school. The family returned to Buczacz in 1917 after the Russians retreated. The area changed hands several more times before the war ended in November 1918.