Fugitive Bohemian Brethren, or Hussites, and the writings of the German Reformers, started the movement in Poland. King Sigismund Augustus (1548-72) favored it, and corresponded with Calvin. The most distinguished Protestant of that country was Jan Laski, or John a Lasco, a Calvinist, who fled from Poland for his faith, was called back by the Protestant nobility, aided by several friends, translated the Bible, and labored for the union of the Reformed and Lutherans (d. 1560). A compromise between the two parties was effected by the general synod of Sendomir in 1570; but subsequently internal dissensions, the increase of Socinianism, and the efforts of the Jesuits, greatly interfered with the prosperity of Protestantism in that country. The German provinces now belonging to Russia; Courland, Livonia, and Esthonia, opened likewise the door to the Reformation, and adopted the Augsburg Confession.