1599 – John Saieninius, the ruler of Krakow, Poland, converted from Calvinism to Socinianism during debates at Rakow and became a patron of Socinian churches and an important benefactor of the movement. He established a Unitarian congregation and his son James established a Unitarian seminary and printing office to aid the grown of Unitarianism. Rakow became the center of the Polish Unitarian community, and its members became known as Rakovians. Read more about the church in Poland here.