This article records tradition as it has been passed down and reported. Its sources are not yet part of the atlas's verified catalogue.
Duke Boleslaw the Pious issued the Statute of Kalisz in 1264, granting the Jews of his territory the freedom to worship, trade and travel under his protection, a charter that later Polish rulers confirmed and extended across the wider Polish lands in the centuries that followed. It was not the first Jewish presence in the region, since a permanent community is recorded at Przemysl as early as 1085, but it gave that presence a legal footing it had not held before.
Settlements grew steadily under that footing through the following centuries, spreading from Przemysl to Lvov, Sandomierz and Kazimierz by the fourteenth century and beyond them into the wider Polish lands. By the middle of the sixteenth century, roughly three quarters of the world's Jews lived in Poland, making it the demographic center of the Jewish diaspora for the next four hundred years.
What this changed for Judaism's spread was the creation, from a single thirteenth century charter, of the largest sustained Jewish population anywhere in the world for four centuries running. The legal protection the Statute of Kalisz first granted in 1264 outlived the duke who issued it by three hundred years, and the community it protected grew, across that time, from scattered settlements into the demographic heart of the entire Jewish diaspora.