One of the most exciting but least known communities in the history of European Reformation is the Unitarian branch, which has become a church community in Poland and Transylvania. In addition to Ferenc Dávid, considered the founder of the Unitarian Church, the lecture will focus on his direct co-workers: the Italian doctor Giorgio Biandrata, the humanist poet Johann Sommer from Pirna, and the Transylvanian Jacobus Palaeologus, sentenced to death by the Inquisition.