Elevation of the nave on the north side. 13th century. The cornice that runs the length of the nave is decorated with busts of popes made in the workshop of Giovanni di Stefano beginning in 1495. Only four or five terracotta molds were used to make the busts, so many of them are identical. Below are 36 busts of Roman and Byzantine emperors from Constantine to Theodosius. Duomo, Siena, Italy.