Livonia in the far northeast was incorporated by Poland in 1561 and Poland entered the Livonian War against Russia. The executionist movement, which attempted to check the progressing domination of the state by the magnate families of Poland and Lithuania, peaked at the Sejm in Piotrków in 1562–63. On the religious front, the Polish Brethren split from the Calvinists, and the Protestant Brest Bible was published in 1563. The Jesuits, who arrived in 1564, were destined to make a major impact on Poland's history.