Summary from Wikipedia

Ivan Šubašić was born in Vukova Gorica, a village along the Karlovac-Rijeka highway in Karlovac district, Croatia. He completed the first grades of elementary school in the neighboring Prilišće and his secondary education in Zagreb. His studies at the Faculty of Theology (the University of Zagreb) were cut short, as he was drafted into the Austro-Hungarian Army. Captured on the Eastern Front, he subsequently joined the Yugoslav volunteers fighting at the Salonica.