Stained-glass window V19, found in the apse area of Duomo, is dedicated to stories from the New Testament. The story of the four Gospels, that today can be admired by walking around the back of the Cathedral, is the work of Giovanni Battista Bertini and his sons Giuseppe and Pompeo, who took care of the reconstruction of the glass originating from the 15th century, the Cathedral's first phase of construction. In this image, it is possible to see the details of the central part of the large window.