Michele Barbieri's Italian translation of Walter Brandmüller's work "Das Konzil von Pavia-Siena 1423-1424" (Paderborn, Munich, Vienna, Zurich 2002) for the Cantagalli publishing house is the first volume in a collection of studies promoted by the Opera della Metropolitana di Siena. A work of immense scientific value, it is the product of lengthy research conducted by an illustrious historian of councils in a vast number of Europe's libraries and archives.