Gabriel Bethlen, the most famous representative of the Iktári branch of the ancient Hungarian Bethlen family, was born at Marosillye (today Ilia in Romania) and educated at Szárhegy (today Lăzarea in Romania) at the Lázár Castle belonging to his uncle András Lázár. Thence he was sent to the court of the Transylvanian Prince Sigismund Báthory, whom he accompanied on his famous Wallachian campaign. Subsequently he assisted István Bocskay to become Prince of Transylvania in 1605 and remained his chief counsellor. Bethlen also supported Bocskay's successor Gabriel Báthory (1608–1613), but the prince became jealous of Bethlen's superior abilities and Bethlen was obliged to take refuge with the Turks of the Ottoman Empire.