Josip Jelačić was born on October 16, 1801 in Petrovaradin, where his father Franjo was sub-marshal of the Slavonian Military Frontier. He was born into a noble family whose members were distinguished warriors, high military commanders, statesmen, priests, educators, benefactors and writers. His mother Ana Portner was also from a noble family, and in addition to Josip, she gave birth to two more sons, Jura and Antun, and a daughter, Cecilia.