The Council of the Opera wrote a long Latin letter at the same time, exhorting their chief to return and satisfy the claims of the Commune. Whether he came or not I cannot say, but it appears not for any length of time, as on March 26, 1436, we find him at Parma, writing a defiant kind of letter to the Operai of San Petronio at Bologna, who had appealed to him to finish his engagements there. By 1439 we find Jacopo della Quercia had died, and his brother Priam was writing repeated petitions to the Opera at Siena about his inheritance from Jacopo, which it seems a certain pupil of Jacopo's called Cino Bartoli was withholding from him.
So the work went on for centuries. There are contracts with different Masters for sculptures, for windows, for towers, for chapels, each Master designing the part assigned to him. Francesco del Tonghio obtained great fame for his carvings of the stalls in the choir in 1377, where his son Giacomo assisted him. We find him in Florence some time later, and his fame must have preceded him, for he is known there as "Francesco of the Choir" (Francesco del Coro).
It is impossible to name a single architect for any of these great buildings; they were all the united work of a self-governed guild.
During the centuries when the Duomo of Siena rose into beauty, her sister of Orvieto also grew under the hands of the same brotherhood.
Lorenzo Maitani, having been trained by his master, Giovanni di Pisa, at Siena, was called to Orvieto in 1310. His family lasted long in the guild, and won much fame. His father Vitale was a master sculptor who had worked under Niccolò and Giovanni. His sons Vitale and Antonio both graduated in the Siena or Orvieto Lodge, and Vitale became chief architect at Orvieto for six months only, on Lorenzo's death, when Master Meo di Nuti di Neri succeeded him.
It is not probable that beyond the design, Maitani had much to do with the façade, which was incomplete till about 1500. The beautiful Bible in stone which adorns the pilasters of the three fine doors may have been designed by Maitani, but the work was done by his sons, with the help of many sculptors of the guild from Siena, Florence, and Lombardy. The upper part was not added till the time of Michele Sanmichele of Verona, who in 1509 was nominated chief architect of the façade at a salary of one hundred florins a year. He is described as "Magistrum Michaelem, Magistri Johannis de Verona, principalem magistrum fabrice faciate de Urbe vetere."[228]
Door in Orvieto Cathedral.