Built in the 13th century in Romanesque-Gothic style, this church was completely destroyed by bombs in 1944. It was reconstructed in 1953. There is the superb mausoleum of Pope Hadrian V, who died in Viterbo in 1276 and the mausoleum of Pope Clement IV, who died in Viterbo in 1268. There are also remains of the tomb of the so-called “Pope-of-one-day”, Cardinal Vicedomino Vicedomini, who would have become Gregory XI, if he had not died the night after his election.