The Cathedral of San Lorenzo (Cathedral of Saint Lawrence) is the cathedral church of the Archdiocese of Genoa and is located in the historic part of the city near the Porto Antico, the tourist port of Genoa. It was consecrated in 1118 by Pope Gelasius II. Construction of the medieval church began around 1100, but it was not completed until the end of the 15th century. Because of this construction history spanning several eras, the cathedral has features of both Romanesque and Gothic architecture.
The first cathedral in Genoa was probably built in the 5th or 6th century and dedicated to the then Bishop San Siro. Excavations under the adjacent stone pavement and the square in front of the current front of the Chiesa di San Siro brought to light Roman wall ruins and road systems, as well as pre-Christian sarcophagi. Accordingly, there was most likely an ancient cemetery on the grounds of the cathedral at that time. The title of cathedral church was later given to the new Cathedral of Saint Lawrence. The construction of the Romanesque church building around 1100 was financed by the successful operations of the Genoese fleet in the Crusades.
The "move" of the cathedral accelerated the urbanization of the city area, which became the center of Genoa with the construction of the city wall in 1155 and the merger of the old city centers of Castrum, Civitas and Burgus. The cathedral was blessed by Pope Gelasius II in 1118 and was given archbishop status in 1133. During battles between the Ghibellines and Guelphs in 1296, the building was badly damaged by fire. Between 1307 and 1312, the facade was completed and the colonnades, including the galleries, were restored. The Romanesque structure of the church had remained largely intact during the work.
In the period between the 14th and 15th centuries, numerous altars and chapels were added. The small loggia on the north-east tower was added in 1455. The one opposite, in the Mannerist style, dates from 1522. In 1550, the architect Galeazzo Alessi was commissioned to reconstruct the cathedral, but only carried out the roofing of the main and side aisles, and the construction of the dome and apse.
The construction of the cathedral was not completed until the 17th century. The dome and the medieval parts of the church were restored between 1894 and 1900.