In Western Europe, hagiography was one of the more important vehicles for the study of inspirational history during the Middle Ages. The "Golden Legend" of Jacob de Voragine compiled a great deal of medieval hagiographic material, with a strong emphasis on miracle tales. Lives were often written to promote the cult of local or national states, and in particular to develop pilgrimages to visit relics. The bronze Gniezno Doors of Gniezno Cathedral in Poland are the only Romanesque doors in Europe to feature the life of a saint. The life of Saint Adalbert of Prague, who is buried in the cathedral, is shown in 18 scenes, probably based on a lost illuminated copy of one of his Lives.