countries gradually adopted the Polish language, Polish manners and customs, the love of Polish freedom and of the Polish commonwealth. The weak middle class was also Polish, not only in Poland proper, but also in the Eastern territories. Only in the north-west, on the borders of Germany, the larger towns contained a considerable percentage of Germans. In the towns, side by side with the Poles, were the Jews, their numbers increasing from west to east. The chief mass of the population, the peasants, were reduced to serfdom, of different races, Polish in Poland proper, Lithuanian, White and Little Russian in the east. In her religion Poland was Roman Catholic. In the sixteenth century, the Reformation had spread powerfully among the nobility throughout the country in the form of Calvinism and Socinianism. But towards the end of the century, with the reign of Sigismund the Third of the Swedish House of Vasa, there came a Catholic reaction, drawing its strength chiefly from Lithuania where Catholicism was confronted by the Eastern faith and was therefore more fervent. Lithuania proper was also Roman Catholic, having been converted from paganism by the Poles. The West Russian provinces belonged in the beginning to the Eastern Church; but in the seventeenth century the larger part of their population was brought within the fold of the Roman Church by the Brest Union by which the Uniats accepted the Roman dogmas, acknowledged the supremacy of the Pope and retained only their ritual. There developed a struggle between the Uniats and the Dis-Uniats, i.e. those who remained in the Eastern Church.
