Pietro Cavallini’s frescoes in Santa Cecilia in Trastevere: recording and reconstruction of the painted decorative system using a tachymeter

Pietro Cavallini, the most important painter of the Middle Ages in Rome, undertook around 1300 the task of decorating the nave of Santa Cecilia in Trastevere with an expansive cycle of frescoes. By applying the frescoes to the walls of the structure which was built some 500 years earlier, a remarkable ensemble was created. Only about ten percent of the original painted decoration has survived because of the complete refurbishing of the church in later centuries; it is no longer visible from the nave. A tachymeter was used to record the still existing fragments of these frescoes on the Carolingian walls. In addition it was possible to reconstruct the highly developed decorative system of the workshop of Cavallini for the first time.