The Protestant Reformation movements made deep inroads into Polish Christianity, which resulted in the establishment of policies promoting religious tolerance, unique in Europe at that time. This tolerance allowed the country to avoid most of the religious turmoil that spread over Europe during the 16th century. In Poland, Nontrinitarian Christianity became the doctrine of the so-called Polish Brethren, who separated from their Calvinist denomination and became the co-founders of global Unitarianism.