The Polish nation adopted Christianity in A.D. 966, but the new faith was very slow in reaching the people, as the services were all in Latin and the clergy were unacquainted with the language of the country. Even the elementary schools were conducted in Latin. The pupils sat in a hut on the bare earthen floor in summer and on bundles of straw in winter.

Except in the institutions in which the instructors were immigrant Germans, where the instruction was given in German, Latin was the only language used in the schools of Poland. The Latin Psalter was the only book in the whole school; the pupils had no exercise books; but they managed to learn some grammar and arithmetic and sang the Latin songs used in the services of the Church. In these circumstances education could make but little progress. Before the end of the thirteenth century the higher clergy issued an edict forbidding the appointment of any person who did not know the Polish language, and enforced the decree with all the authority of the Church; but, as in other European countries, Latin was the official language of the Polish University. The Academy of Cracow was founded by Casimir the Great and raised to the status of a University in 1400, richly endowed by the young Queen Jadwiga, who at her death bequeathed to it all her jewels.

In the sixteenth century the University attained great fame, and Germans, Czechs, Hungarians, and Swiss came in numbers to hear the lectures of the professors, especially the great astronomer Copernicus.