In modern eyes, the most saliently liberal aspect of Jagiellon Poland is its exceptional toleration of religious dissent. This tolerance prevailed in Poland even during the religious upheavals, war, and atrocities associated with the Protestant Reformation (see Glossary) and its repercussions in many parts of sixteenth-century Europe. The Reformation arrived in Poland between 1523 and 1526. The small Calvinist, Lutheran, and Hussite groups that sprang up were harshly persecuted by the Roman Catholic Church in their early years. Then in 1552 the Sejm suspended civil execution of ecclesiastical sentences for heresy. For the next 130 years, Poland remained solidly Roman Catholic while refusing to repress contending faiths and providing refuge for a wide variety of religious nonconformists.

Such broad-mindedness derived as much from practical necessity as from principle, for Poland-Lithuania governed a populace of remarkable ethnic and religious diversity, embracing Roman Catholics, Eastern Orthodox, Protestants, and numerous nonChristians . In particular, after the mid-sixteenth century the Polish lands supported the world's largest concentration of Jews, whose number was estimated at 150,000 in 1582. Under the Jagiellons, Jews suffered fewer restrictions in Poland-Lithuania than elsewhere in Europe while establishing an economic niche as tradesmen and managers of noble estates.

Data as of October 1992