Poles and Jews
A legend tells of a Jew, Abraham Prochownik, being chosen by lot to lead Poles before the year 900. The Jews who came eastward from – or at any rate across – Germany brought with them their Middle High German speech, which, by the eighteenth century, separated from its German origins. In the course of the eighteenth century, Yiddish – which also came to be known as 'jargon' – absorbed many 'local', Polish and Russian words and acquired an extensive literature, mostly in the nineteenth century. Casimir the Great had no legitimate issue; his great-niece and heir Jadwiga married the Lithuanian Grand Duke Jagilo/Jagiello in 1386. He was the last pagan among European rulers, and the incorporation of his vast, Ruthenian-speaking lands completely changed the configuration of the country, and also brought a rather different Jewish population in contact with the German/Yiddish-speaking settlers from Western Europe.