The Basilica of Maxentius and Constantine (Basilica di Massenzio) is the largest ancient building in the Roman Forum. Construction began on the northern side of the forum under the emperor Maxentius in 308, and was completed in 312 by Constantine I after his defeat of Maxentius at the Battle of the Milvian Bridge. The building rose close to the Temple of Peace, at that time probably neglected, and the Temple of Venus and Rome, whose reconstruction was part of Maxentius' interventions.
The building consisted of a central nave covered by three groin vaults suspended 39 meters above the floor on four large piers, ending in an apse at the western end containing a colossal statue of Constantine (remnants of which are now in a courtyard of the Palazzo dei Conservatori of the Musei Capitolini).
The south and central sections were probably destroyed by the earthquake of 847. In 1349 the vault of the nave collapsed in another earthquake. The only one of the eight 20-meter-high columns, which survived the earthquake was brought by Pope Paul V to Piazza Santa Maria Maggiore in 1614. All that remains of the basilica today is the north aisle with its three concrete barrel vaults. The ceilings of the barrel vaults show advanced weight-saving structural skill with octagonal ceiling coffers.References:
The eight towns in south-eastern Sicily, including Ragusa, were all rebuilt after 1693 on or beside towns existing at the time of the earthquake which took place in that year. They represent a considerable collective undertaking, successfully carried out at a high level of architectural and artistic achievement. Keeping within the late Baroque style of the day, they also depict distinctive innovations in town planning and urban building. Together with seven other cities in the Val di Noto, it is part of a UNESCO World Heritage Site.
In 1693 Ragusa was devastated by a huge earthquake, which killed some 5,000 inhabitants. Following this catastrophe the city was largely rebuilt, and many Baroque buildings from this time remain in the city. Most of the population moved to a new settlement in the former district of Patro, calling this new municipality 'Ragusa Superiore' (Upper Ragusa) and the ancient city 'Ragusa Inferiore' (Lower Ragusa). The two cities remained separated until 1926, when they were fused together to become a provincial capital in 1927.