San Nazaro in Brolo church was built by St. Ambrose starting from 382 on the road that connected Milan (then Mediolanum) to Rome. It was originally dedicated to the Apostles, and thus known as Basilica Apostolorum.
As explained by an inscription in the church written by Ambrose himself, the church's plan was on the Greek Cross with apses on the arms, a feature present only in the Church of the Holy Apostles in Constantinople. In front of the basilica was a porticoed atrium. Under the basilica's altar were housed the relics of the Apostles, which are still present. In 397, when the body of St. Nazarus was discovered, a new apse was created. Serena, niece of emperor Theodosius I, donated the marbles for the sacellum housing the relics and also embellished the rest of the church.
The apse of the right arm has a portal with a false porch. The ceiling of the nave, originally consisting of wooden spans, was replaced by a groin vault during the Middle Ages. The walls are original. Also in this age the Romanesque-style octagonal tambour, featuring a circular loggia with small columns, was added over the arms' crossing.
Starting from 1512, Bramantino built the Trivulzio Mausoleum, which obstructs the Palaeo-Christian façade.References:
The famous Italian Medici family have given two queens to France: Catherine, the spouse of Henry II, and Marie, widow of Henry IV, who built the current Luxembourg palace. Maria di Medici had never been happy at the Louvre, still semi-medieval, where the fickle king, did not hesitate to receive his mistresses. The death of Henry IV, assassinated in 1610, left the way open for Marie's project. When she became regent, she was able to give special attention to the construction of an imposing modern residence that would be reminiscent of the Palazzo Pitti and the Boboli Gardens in Florence, where she grew up. The development of the 25-hectare park, which was to serve as a jewel-case for the palace, began immediately.
The architect, Salomon de Brosse, began the work in 1615. Only 16 years later was the palace was completed. Palace of Luxembourg affords a transition between the Renaissance and the Classical period.
In 1750, the Director of the King's Buildings installed in the wing the first public art-gallery in France, in which French and foreign canvases of the royal collections are shown. The Count of Provence and future Louis XVIII, who was living in Petit Luxembourg, had this gallery closed in 1780: leaving to emigrate, he fled from the palace in June 1791.
During the French Revolution the palace was first abandoned and then moved as a national prison. After that it was the seat of the French Directory, and in 1799, the home of the Sénat conservateur and the first residence of Napoleon Bonaparte, as First Consul of the French Republic. The old apartments of Maria di Medici were altered. The floor, which the 80 senators only occupied in 1804, was built in the middle of the present Conference Hall.
Beginning in 1835 the architect Alphonse de Gisors added a new garden wing parallel to the old corps de logis, replicating the look of the original 17th-century facade so precisely that it is difficult to distinguish at first glance the old from the new. The new senate chamber was located in what would have been the courtyard area in-between.
The new wing included a library (bibliothèque) with a cycle of paintings (1845–1847) by Eugène Delacroix. In the 1850s, at the request of Emperor Napoleon III, Gisors created the highly decorated Salle des Conférences, which influenced the nature of subsequent official interiors of the Second Empire, including those of the Palais Garnier.
During the German occupation of Paris (1940–1944), Hermann Göring took over the palace as the headquarters of the Luftwaffe in France, taking for himself a sumptuous suite of rooms to accommodate his visits to the French capital. Since 1958 the Luxembourg palace has been the seat of the French Senate of the Fifth Republic.