Works of Protestant reformers in the collections of the Lutheran High School in Mediaș. Since 2018, our research has been conducted in the historical libraries of Transylvania, focusing on the works of fifteen Western European Protestant theologians, known as reformers, who were active in the 16th century. At the Lutheran Gymnasium library in Mediaș, we discovered 58 theological texts by these authors. This number is representative of the average size of the collections we have examined.