This volume is dedicated to the groundbreaking architecture and the uniquely preserved stained glass of the famous cathedral. Based on a comprehensive presentation of the sacred site from the time of the Druid sanctuary through the reconstruction by Bishop Fulbert at the turn of the millennium, to the devastating fire of 1194 and the construction of the first classical cathedral, a novel formulation of the High Gothic building principle is presented, which also clarifies the motifs of many technical innovations of that time. The individual architectural elements, such as the enigmatic labyrinth on the western church floor or the rose window of the west façade, are examined for their internal connections and recognized as consistently interrelated visual elements of a spiritual journey through their juxtaposition with the design of the west portal.