The Sandomierz Agreement was an agreement reached in 1570 in Sandomierz between a number of Protestant groups in the Polish–Lithuanian Commonwealth. It was intended to unite different creeds of the Protestant Reformation, such as the Calvinists, the Lutherans, and the Bohemian Brethren, and to face Counter-Reformation as a united front. The Polish Brethren did not participate in the talks that resulted in the agreement, signed on April 14, 1570. Signatories of the consensus agreed to respect each other's preachers and sacraments. Furthermore, united synods were planned. The idea of a parliament bill was raised, in which Protestants were to be treated on equal terms with Catholics.