The two were elected simultaneously (Damasus' election was held in San Lorenzo in Lucina). J. N. D. Kelly states that Damasus hired a gang of thugs that stormed the Julian Basilica, carrying out a three-day massacre of the Ursinians. Thomas Shahan says details of this scandalous conflict are related in the highly prejudiced "Libellus Precum" (P.L., XIII, 83-107), a petition to the civil authority on the part of Faustinus and Marcellinus, two anti-Damasan presbyters. Such was the violence and bloodshed that the two prefects of the city were called in to restore order, and after a first setback, when they were driven to the suburbs and a massacre of 137 was perpetrated in the basilica of Sicininus (the modern Basilica di Santa Maria Maggiore), the prefects banished Ursinus to Gaul. Both Cynthia White and Edward Gibbon have suggested a quid pro quo between the prefect Praetextatus and Damasus to secure his election and exile Urbanus, in return for Damasus's support of Praetextatus's power in Pagan circles. There was further violence when he returned, which continued after Ursinus was exiled again.