 Around 1549–1550, he briefly visited Italy and probably spent a few months attending lectures at the Padua University.Upon his return, he joined the army of Ferdinand I, Holy Roman Emperor, and took part in his military struggle against the Turks.Some time after 1553, Báthory was captured by the Turks, and after Ferdinand I refused to pay his ransom, joined the opposing side, supporting John II Sigismund Zápolya in his struggle for power in the Eastern Hungarian Kingdom.