Ibrahim Müteferrika, the Hungarian convert to Islam who set up the first Turkish printing press. He was born in the town of Kolozsvár in 1670 and probably was the first European who played an important role in the modernization of Turkey.
His Hungarian name is shrouded in darkness to the present day.

According to Niyazi Berkes he was a Hungarian Unitarian.

Unitarian faith accepts one god and denies the holy trinity, it is an anti-trinitarian faith and believes that Jesus was not God, but only man. It does not worship Jesus,only follows his teachings.
The largest group of Unitarians outside America live in Hungary and Transylvania. King János Zsigmond (John Sigismund) the unitarian
king of Transylvania promulgated the Edict of Torda in 1568,the complete religious freedom.

As power shifted after the death of the king Unitarianism became illegal and persecuted both by Calvinists and Catholics. And it continued in the beginnings of Austrian rule , unitarians were labeled Judaizers and Islamizers.

Many unitarians took refuge in Turkey. (Also is to be noted that leaders of the anti-Habsburg struggle - thus the emigration of Thököly at the end of the 17th century, Ferenc Rákóczi in the early 18th century and Lajos Kossuth in the middle of the 19th century - regularly sought and found refuge in the Ottoman Empire. Memories associated with them are to be found in Izmir, Tekirdag and Kütahya. The population of Tekirdag left the areas made available to Rákóczi and his group of emigres untouched until the end of the 19th century, as they were considered the 'land of the Hungarian king'.)

According to Niyazi Berkes Ibrahim Müteferrika took refuge in Turkey and was not captured and sold as slave as many of his biographers write in order to excuse his apostasy. His work Risale-i Islamije in fact is not a defence of Islam but a polemic against Catholicism and Trinity and it shows in fact that he was a Unitarian. His Unitarism explains the ease of his conversion to Islam.

The name Müteferrika means royal quartermaster or as a title indicates membership of a kind of elite guard corps attached to the sultan's person.

Material used:
The development of secularism in Turkey By Niyazi Berkes, Feroz Ahmad
In Turkish