A Romanesque church was built here from 1088 to 1093[1] to commemorate a victory on August 6, 1087, by the navies of Genoa and Pisa against a raiding Arab fleet; since Pope Sixtus II was honored on that date, the church was dedicated to him. The church belonged to the Benedictine Order of monks allied with Sacra di San Michele till 1479, except 1217–1241.