Pantheon – Rome
The Pantheon in Rome is a monumental building, dating back to the Roman imperial period, a catholic church and, with over seven million visitors in 2016 (Source: MIBACT – Italian Ministry of Culture), Italy’s most visited state-owned cultural site.
The first Pantheon (whose name means “(temple) of all gods”), was erected in the 1st century B.C. (probably between 27 and 25 B.C) by Roman politician and general Marcus Agrippa, whose name is reported in the inscription “Marcus Agrippa, Lucii filius, consul tertium fecit” (built by Marcus Agrippa, son of Lucius, consul for the third time)* still visible on the building’s pediment. Little remains of Agrippa’s temple, since it was largely destroyed by a fire and rebuilt in different form in the 2nd century A.D.
The construction of the “second” Pantheon was promoted by Emperor Hadrian; the temple was completed between 125 and 128 A.D. probably after a design by Syrian-Roman architect Apollodorus of Damascus.
In 609, after the fall of the Roman Empire, the “temple of all gods” was converted by Pope Benedict V into a Christian church and renamed Sancta Maria ad Martyres (Saint Mary of the Martyrs). This arguably saved the building either from destruction or from being used as a quarry during the Middle Ages, as it happened to many other ancient buildings in Rome.
In the 17th century two small Baroque-style bell towers, designed by Francesco Borromini, were added to the building. Yet, the towers were not much appreciated by the Roman people and scornfully nicknamed “donkey’s ears”; they were eventually removed in 1883.
* The Latin inscription on the pediment is in a condensed form, and it actually reports “M.AGRIPPA.L.F.COS.TERTIVM.FECIT”
The Pantheon’s pediment; photo: cesareb
A 19th century painting of the Pantheon’s square by Ippolito Caffi which still shows the two “donkey’s ears” bell towers designed by Francesco Borromini in the 17th century
The Pantheon consist of a portico and an imposing circular hall, the Rotunda.
The portico features sixteen large monolithic columns, made in gray and pink Egyptian granite, topped by Corinthian-style white marble capitals. The pediment was originally decorated with a bronze frieze, now lost; the porch roof is made in timber and covered with bronze plates. From the portico, a large bronze door 7.53 meters (24,7 feet) high leads to the Rotunda interior space.
The Rotunda is a huge cylinder-shaped space, covered by a coffered hemispheric dome. The cylinder is 21.7 meters (71,2 feet) in radius and 21.7 meter-high from the floor to the dome springing level. Overall, the entire interior volume of the Rotunda, dome included, can be inscribed in a perfect cube with an edge of 43.4 meters (142.4 feet) or, in other words, it could contain a giant balloon of the same diameter.
The Rotunda’s walls are made in Roman concrete – a mixture of sand, hydraulic mortar, volcanic dust **, silica powder, and aggregates – poured into a sort of permanent formwork made in bricks, clearly visible from the outside.
The internal walls are covered in stucco and clad with various types of marble; six niches and a semicircular apse open on the hall’s internal perimeter.
The geometric-patterned polychrome floor is made in porphyry, white and yellow marble, and red granite. The Rotunda rests on a massive foundation ring, 4.5 meters (14.8 feet) high, also made in concrete. A complex system of arches, vaults, pillars, and buttresses transfers the building’s structural loads to the foundations.
The dome is also made in Roman concrete covered in monochrome stucco; 43.4 meters across, the Pantheon’s is still the world’s largest dome in unreinforced concrete.
A circular opening 8.92 meters (29.2 feet) across, the oculus, is located at the apex of the dome to provide natural lighting and ventilation to the hall.
** A specific family of volcanic dusts, pozzolans, is thought to be largely responsible of the particular strength of the Roman concrete, also known as or opus caementicium: pozzolan, mixed with (sea)water and quicklime, produces in an anaerobic environment by-products similar to those of the Portland cement in the same conditions through the chemical reaction: Pozzolan + CH + H => C-S-H + C-A-H (the reaction written in standard chemist notation is Ca(OH)2 + H4SiO4 → CaH2SiO4·2 H2O). Though, studies by the University of California at Berkeley, the University of Utah, and others, suggest that other more complex reactions involving the presence of zeolites and other types of volcanic ashes in Roman architectural mortar also contribute to the exceptional strength and durability of Roman concrete.
Andrea Palladio, plan of the Pantheon, from “The Four Books of Architecture”, 1570
Transverse section of the Pantheon, from a 1682 engraving by Antoine Babuty Desgodets; image courtesy of Khan Academy
Geometrical scheme of the Pantheon’s proportions
The Pantheon in Rome; photo: Alexander Russy
Influence on architecture
Along with the Parthenon in Athens, the Pantheon is probably the word’s most famous antique building, and the archetype of countless structures built in the last nineteen centuries.
It directly inspired designs such as those of Andrea Palladio’s villa La Rotonda in Vicenza, the Panthéon (formerly church of Saint Genevieve) in Paris by Jacques Germain Soufflot, Thomas Jefferson’s Rotunda at the University of Virginia in Charlottesville, the Great Dome of the MIT in Boston, The National Gallery of Art’s West Building, and the Jefferson Memorial by John Russell Pope, both in Washington D.C., to name just a few.
The Jefferson Memorial in Washington, D.C., designed by John Russel Pope in the 1930s; photo: Anthony Citrano
The Panthon is still a church which, since the 16th century, is also the burial place of famous artists, including Rapahel, Annibale Carracci, and Jacopo Barozzi da Vignola and renowned violinist and composer Arcangelo Corelli.
The church also contains the monumental tombs of the first two Kings of Italy, Victor Emmanuel II and his son Umberto I.
Differently from other historical buildings in Rome, the Pantheon does not feature many notable artworks, apart from itself; the most important art piece on view in the building is arguably the fresco painting The Annunciation (15th century) by Melozzo da Forlì.
The Pantheon is located in the heart of Rome, not far from Piazza Navona; the nearest underground station is Barberini (line A); for the time being, access to the monument is free-of-charge.
Interior of the Pantheon’s Rotunda, photo: Lee Varis
Melozzo da Forlì, Annunciation, fresco painting, 15th century
Aerial view of the Pantheon from north; photo: Bing
View or the Pantheon at dusk; photo: Mathieu Schoutteten
The dome with the oculus circular opening; photo: Meldarion Quesse
An interior view which shows the wall decoration and the polychrome floor of the Rotunda; photo: Carole Raddato
Cover image: the Pantheon in Rome, view from Via del Pantheon; photo: Luc Mercelis