This is considered one of the most honorable most works of the Renaissance. In reality the works for the construction of this amazing monument were based on the preceding structure of the 14th Century Romanesque-Gothic church of San Francesco. Sigismondo Pandolfo Malatesta began the work in 1449: the architectural part was entrusted to Matteo de' Pasti, the sculpture was the domain of Agostino di Duccio and the external architecture was the work of Leon Battistia Alberti. The architect planned a new concept in marble recladding, getting rid of all Gothic design and each decorative accent, and drawing on inspiration from the Roman Arco d'Augusto instead. The majestic façade inspired by classic Renaissance forms, even if it remains unfinished in the upper part, it is distinguished from the internal, creating an architectural contrast. One of its six inside chapels, la Cappella degli Antenati housed the Arca degli Antenati dei Discendenti work of Agostino di Duccio in which Sigismondo wanted to have united the of his ancestors and the ancient of the Casata. Giotto's crucifix of 1312 is in the temple and in the Capella delle Reliquie you can see the fresco of Piero della Francesca (1451) of Sigismondo kneeling in front of Saint Sigismondo.