The Peace of Westphalia of 1648 set a rule for religious disputes in the Holy Roman Empire. In matters of religion, and whenever the Catholic and the Protestant estates separated into two groups, soll allein gütlicher Vergleich die Streitigkeiten schlichten, ohne Rücksicht auf die Stimmenmehrheit. Only an amicable settlement shall decide the disputes, without regard to the majority of votes. The Latin text calls it amicabilis compositio.
The separation into two groups was called itio in partes. As a result, the Protestant minority could not be outvoted at the Imperial Diet in religious questions.