The Hauteville dynasty ruled Sicily from 1072 to 1194, and the most important interventions of the Norman period involved the readaptation of such ancient buildings as S Giovanni alle Catacombe. The Catacombs of St. John sprang up around the tomb of San Marciano (St. Martian), first bishop of Syracuse, and date from the fourth-fifth century. They developed from existing Roman catacombs, but are cut from limestone and have much larger chambers with frescoes. The Basilica of St. John the Evangelist, built by the Normans, was erected over an ancient crypt of the martyr San Marciano. The first church on the site dated from the 6th century; this fell into disuse during the Arab period and was rebuilt in the 11th century. Abandoned again, it was redeveloped by the Carmelites in 1636. It was destroyed in the 1693 earthquake and rebuilt with material on the site. It is only partly restored and has no roof. The main altar is Byzantine.