Sigismondo Malatesta commissioned Leon Battista Alberti to transform this church in 1447. He built an ancient-style temple to celebrate the glory of the dynasty, later becoming their mausoleum. This building is exquisitely decorated in the late-Gothic style by Antonio di Duccio and has some striking pieces, such as a superb painting by Piero della Francesca depicting Sigismondo before his patron saint, a crucifix by Giotto, and the tomb of Isotta Malatesta supported by elephants.