The first version of this church goes back to the 7th century A.D., when it had only a central nave. Consecrated in A.D. 780 during Longobard domination, two naves were added in the 9th century and two others in the 12th century. The structure was then restored and redecorated in the 18th century, at which point it became known as one of the most beautiful Romanesque churches in Italy. However, the U.S. bombing in 1943 destroyed almost the entire ancient church, saving only the bell tower and the elegant Romanesque facade, a 13th-century Pisan-style marvel of striped marble and rich carvings. The richly carved jambs of the central portal date from the 12th century; they once bracketed 13th-century sculpted bronze doors which were considered rivals of the famous ones of Florence's baptistery. They were blown to pieces by the bombing, and what was saved was painstakingly restored; you can now see the 72 frames that composed the doors displayed inside the church. The top 43 are decorated with scenes from the life of Christ, from the Annunciation to the Ascension, while the bottom 29 depict local religious personalities. The Museo Diocesano -- housed partly in the crypt and partly in the adjacent Palazzo Arcivescovile, Piazza Orsini 27 (tel. 0824-42825) holds remains from the destroyed Duomo, including what was left of the extremely rich treasure. Note: At presstime, the Duomo was closed for restorations and no date was given for the reopening.