From a seliḥah by Rabbi Moshe Katz Narol of the exiles of Poland, head of the Beth Din of the Holy Congregation of Metz:

We did not know, but our fathers told us how the exiles of Israel came to the land of Polin (Poland). When Israel saw how its sufferings were constantly renewed, oppression increased, persecutions multiplied, and how the evil authorities piled decree on decree and followed expulsion with expulsion, until there was no relief for Israel, they went out on the road and sought an answer from the paths of the wide world—which is the correct road to take to find rest for one's soul. Then a piece of paper fell from heaven:

Go to Polaniya (Poland)!

So they came to the land of Polin and they gave a mountain of gold to the king, and he received them with great honour. And God had mercy on them, so that they found favour with the king and the nobles. And the king gave them permission to reside in all the lands of his kingdom, to trade over its length and breadth, and to serve God according to the precepts of their religion. And the king protected them against every foe and enemy.

And Israel lived in Polin in tranquillity for a long time. They devoted themselves to trade and handicrafts. And God sent a blessing on them so that they were blessed in the land, and their name was exalted among the peoples. And they traded with the surrounding countries, and they also struck coins with inscriptions in the holy script and the language of the country. These are the coins which have on them a lion rampant from the right facing left. And on the coins are the words ‘Mieszko, King of Poland’ or ‘Mieszko, Krol Polski’. The Poles call their king ‘Król’.

When they first arrived from the land of the Franks, they found a forest in the land, and on every tree a tractate of the Talmud was carved.