Gabriel Bethlen (; 15 November 1580 – 15 November 1629) was Prince of Transylvania from 1613 to 1629 and Duke of Opole from 1622 to 1625. He was also King-elect of Hungary from 1620 to 1621, but he never took control of the whole kingdom. Bethlen, supported by the Ottomans, led his Calvinist principality against the Habsburgs and their Catholic allies. Early life Gabriel was the elder of the two sons of Farkas Bethlen de Iktár and Druzsiána Lázár de Szárhegy. Gabriel was born in his father's estate, Marosillye (now Ilia in Romania), on 15 November 1580. Farkas Bethlen was a Hungarian nobleman who lost his ancestral estate, Iktár (now Ictar-Budinț in Romania), due to the Ottoman occupation of the central territories of the Kingdom of Hungary. Stephen Báthory, Prince of Transylvania, granted Marosillye to him and made him captain-general of the principality. Druzsiána Lázár was descended from a Székely noble family. Both Farkas Bethlen and his wife died in 1591, leaving their two sons, Gabriel and Stephen, orphaned. The brothers were put under the guardianship of their maternal uncle, András Lázár de Szárhegy. They lived in the Lázár Castle in Szárhegy in Székely Land (now Lăzarea in Romania) for years. Gabriel's court historian, Gáspár Bojti Veres, described Lázár as a "grumpy and fierce" soldier who did not care much about their formal education. According Gabriel's first extant letter (from 1593), Sigismund Báthory, Prince of Transylvania, seized the brothers' estates "at the word of many coaxing people" without paying a compensation to them in 1591 or 1592, but a "few primary kinsmen" convinced the prince to offer restitution or other landed property to them. Gabriel also mentioned in the letter that he decided to visit the prince's court in Gyulafehérvár (now Alba Iulia in Romania). Career Beginnings Modern historians try to reconstruct the major events of Gabriel's youth based on sources (primarily memoirs and letters) completed decades later, because only two documents written between 1593 and 1602 mentioned him. One of the later sources is Gabriel's own letter from 1628, in which he stated that Stephen Bocskai had raised him and "placed great credence" in him. Gabriel also stated that Bocskai was his "kin". Another important source was written by Gabriel's retainer, Pál Háportoni Forró, who stated that Gabriel had held "great and honorable offices" and performed "the greatly laborious duties of emissary" in his youth. Based on these sources,