Gębarowicz was born in Jarosław, one of three sons in a patriotic Polish family. His mother was Bronisława, née Smolek. His father, Teofil, was a railway engineer who served as assistant station master in Stanisławów and later as station master in Buczacz. In 1912 he completed his schooling at Buczacz Lyceum and was already a member of two youth organisations, "Zet" and "Zarzewie". He went on to study History and the History of Art at Lwów University. His studies were interrupted by the outbreak of World War I when he served in the ranks of the Austro-Hungarian Army (1915–1918). At the end of that conflict he took part in the Defence of Lwów with Polish forces during the Polish–Ukrainian War, after which he was able to graduate.