ENThe Crown Tribunal and the Lithuanian Tribunal as the highest court instances for noblemen played an important role in the jurisdiction of the Polish Kingdom in the earlymodern period. Noblemen considered the institutions to be the most important foundations of their privileges in Poland. Tribunal courts strengthened the position of the nobility and weakened the position of the monarch. Th us, both tribunals went beyond their role as courts of appeal and were becoming almost governing bodies. It was particularly noticeable in some rulings issued in religious matters, where the diff erence between both tribunals – in the Crown and the Grand Duchy of Lithuania- is best seen – at least in the fi rst decades of their existence. Comparing the rulings of the Lithuanian and Crown Tribunal in religious matters in the 16th century and the fi rst half of the 17th century gives us an answer to the question about the real power of people of another faith not only in tribunal courts but indirectly also in both united states. A considerably stronger position of non-Catholics in Lithuania resulted from the fact of a stronger impact of the Reformation there. To some extent Lithuanian evangelicals owed it to their affl uent protectors – the Radziwiłł family from Biržai. Besides, in the Tribunal the Protestants could count on the support of the Orthodox Church ( and vice versa). Th us, the Lithuanian Tribunal constituted an important forum of cooperation of evangelicals and the “Disunited” in the protection of religious freedom during the development of the Counter-Reformation in Poland.The fact that members of the Orthodox Church inhabited almost all the area of the Grand Duchy of Lithuania, and in the eastern part of the country constituted an absolute majority, aff ected the composition of the tribunal court. Protestants and members of the Orthodox Church cooperated with each other, thanks to which they succeeded in resisting the Counter-Reformation trends. Tolerant Catholics, including the clientele of the Radziwiłłs from Biržai, also contributed to the fact that sentences of the tribunal courts were positive for non-Catholics. The difference between rulings in religious matters issued by the Lithuanian Tribunal from the rulings given by the Crown Tribunal resulted from the specific religious situation in the Grand Duchy of Lithuania. The Lithuanian Tribunal, becoming the place of struggle for religious freedom for non-Catholics at the turn of the 16th and 17th centuries, constituted a forum of disputes with Sigismund III, who advocated the Counter-Reformation. The King cancelled the rulings issued by the Lithuanian Tribunal in religious matters, using the assessor’s court, the main aim of which was to try burghers from royal towns. In reality, both the King and the Tribunal operated on the edge of the law in religious cases, oft en surpassing their rights. Key words: Religious relations in Poland in the 16th-17th centuries; The judiciary- the Counter-Reformation- the Orthodox Church – Protestants- the Union of Brest. [From the publication]