The Pantheon of Rome

Construction

The construction of the Pantheon was carried out in two times.

The Pantheon of Agrippa

The original Pantheon was built in -27, at the beginning of the reign of Octave Auguste, by Marcus Vipsanius Agrippa, companion of Auguste, who took part thus in the policy of embellishment of the City, encouraged by Auguste. It built the Pantheon and the thermal baths of Clutched in margin of the urbanized part of Rome, close to the Champ de Mars, area favourable with the great urban developments.

The date of this construction corresponds to the third mandate of Consul of Clutched, whose name is engraved on the gantry of entry. On this inscription, one can read: M.AGRIPPA.L.F.COS.TERTIVM.FECIT what means “Marcus Agrippa, wire of Lucius, consul for the third time, made it build”. This third consulate goes back to -27. However, a slightly different date is sometimes quoted, -25, to which Dion Cassius draws up the list of the works completed by Agrippa on the Champ de Mars.

According to excavations led to the end of the 19th century, the first temple was rectangular, with a Pronaos (left former the temple) open towards the south, and a concealed (left interior and closed temple) transverse broader (approximately 40 meters) that long. It was built in blocks of Travertin and was covered plates of marble. According to the use, it was surrounded by a free space, today partly occupied by the temple of Hadrian, and bordered in the south by the basilica of Neptune.

Pline Old the (23-79) praised decoration external of this temple:

It is also out of bronze of Syracuse that are the capitals of the columns of the Pantheon placed by Mr. Agrippa
the Pantheon of Agrippa was decorated by Diogène with Athens, and the Cariatide S which are with the columns of this temple pass for masterpieces, as well as the statues posed on the ridge .

The Pantheon of Hadrian

The Pantheon of Agrippa was destroyed by a new fire in 110, under Trajan. It was entirely rebuilt under the reign of the emperor Hadrian, about the year 125, as the dates printed in bricks, ranging between 123 and 125 reveal it. One can suppose that Hadrian inaugurated it at the time of his stay prolonged in Rome between 125 and 128. It made even use occasionally as court of it, returning justice in company of some senators.

The plan of the new building is exceptional, without precedent in Roman architecture. The influence of Hadrian on the design of the building is possible, if one considers the originality of the architecture of the villa which it was made build close to Rome. The visitor who crosses traditional the Pronaos with columns of the Pantheon leaves a world rectilinear and luminous to be wrapped in the half-light of a concealed circular and either rectangular, surmounted by an immense cupola. Temples with concealed round were built at the time antiquated, like the Temple of Vesta or the temple of Hercules Victor, but in dimensions much more modest, and never coupled with a traditional porch.

Symbolism of the monument

According to Dion Cassius, the temple sheltered many statues, of which those of Arès, (Mars), father of Romulus, that of Aphrodite, (Come), ancestral divinity of the people Iulia, like that of divine the Jules César. Always according to Dion Cassius, Auguste would have pushed back the suggestion of Clutched to add his own statue to the three preceding ones, only agreeing to appear in the pronaos. The entry was thus kept on both sides by the statues of Auguste and of Clutched, all two consuls in 27 av. J. - C., which respected seemingly the republican parity of the capacities and confirmed the rise of Clutched like potential heir to Auguste

Rather than an imperial worship which then did not dare to be posted like such, the Roman leaders proposed a vaster worship and more neutral, that of all the gods, “the Pantheon”, thus named by Pline Old the.

Hadrian was a cosmopolitan emperor which travelled much in the East, and which was a large admiror of the Greek culture. It seems that, for him, the Pantheon, was to be the temple of all the gods, a kind of gesture oecumenical or syncretic with the address of all those which in the Roman Empire did not adore the old divinities of Rome, or who adored them under other names. However, according to Pierre Stierlin and in a more obvious way, by combining the sphere and the circle, Hellenic symbols of perfection, with the solar presence, Photogravure, divinity incarnated by the kings in the East, Hadrian implicitly amplified the imperial worship, according to an orientalizing tendency which its successors will continue. Consequently, when Hadrian returns legal decisions in his Pantheon, exceptional use for a temple, it would be put in scene like an emanation of the Photogravure royal. In the Memories of Hadrian , Marguerite Yourcenar place in the mouth of Hadrian this vision of the Pantheon, compatible with what we know of the Roman thought:

I had gone up for the structure even of the building at primitive and fabulous times of Rome, with the round temples of the ancient Étrurie. I had wanted that this sanctuary of all the Gods reproduced the form of the Globe and the stellar sphere, of the sphere where contains all the seeds of fire eternal, of the hollow sphere which contains all. It was also the form of these Hutte S ancestral where the smoke of the oldest human hearths escaped by an opening located at the ridge. The cupola, built of a hard and light lava, which seemed to still take part in the upswing of the flames, communicated with the sky by a large hole alternatively black and blue. This open and secret temple was designed like a Sundial. The hours turned in round on these boxes carefully polished by the Greek craftsmen; the disc of the day would remain suspended there like a gold shield; the rain would form on the pavement a pure puddle pool; the prayer would escape as a smoke towards this vacuum where we put the gods. (Marguerite Yourcenar, Memories of Hadrian, 1951, Plon)

Structure of the building

Technical context

According to certain authors, the design of the new building could be the work of Apollodore of Damas, contemporary architect of Hadrian and particularly tested. Unfortunately, no document attests this assumption. At all events, the Romans had a perfect command of the techniques of the art of the building, after the impulse brought by the innovative projects of Néron, followed colossal achievements of the Flaviens and Trajan. The Roman experiment in the construction of vast cupolas is attested by the cupola in the Domus aurea of Néron and by the archaeological vestiges of thermal baths of Baïes: cupola of 26 m to alleged “the temple of Come”, of 29,5 m to the “temple of Diane”, and 38 m to the temple of Apollo, close to Bays, all former to the reign of Hadrian on formwork were the knowledge to make Roman which contributed to the rebuilding of the Pantheon. Esthetics was not in remainder, as the analysis shows it below many geometrical effects, decorative choice of materials and work on the interior lighting of the temple.

Overall plan

The rebuilding of the Pantheon preserved the North-South axis of the building, but reversed the orientation of the entry and directed it towards north. The Pronaos and the building of transition with the rotunda occupied the site of the old building, and the rotunda fills space between the old entry and the basilica of Neptune. The new temple was surrounded by a Portique on three with dimensions of approximately 60 m out of 120 m, and was preceded by a paved yard of Travertin.

The pavement of the ground, restored perfectly, is in marquetry of coloured stone slabs (Opus sectile), and draws a squaring where plates of porphyry alternate and of Granite gray forming reasons alternatively round and square. To facilitate the drainage of rain which penetrates by the opening of the cupola, this pavement is slightly convex, with a heightening of 30 cm to approximately 2 m of the center of the rotunda.

The cupola

Internally, the vault fits in a perfect sphere of 150 Roman feet, that is to say 43,30 m of diameter, a height equalizes 43,30 Mr. This sphere theoretical is thus tangent on the surface of the ground. It is ribbed by 140 boxes in Stuc, laid out on five lines of decreasing size which leave free the cap of the top. This cap is bored of a central Oculus of 8,7 m of diameter.

An attentive observation of the boxes shows that the rectangles which model them are slightly upwards eccentric. Indeed, these mouldings are not centered on the medium of the sphere registered in the cupola, but on the basis of this sphere, which corresponds to the center of the ground of the rotunda. This subtle correction creates an effect of radiant prospect for the observer which is held with the center of the temple.

The summit Oculus is reinforced by a bronze circle. It is the single direct source of light, because the entry of concealed is turned towards north and is protected by the pronaos. It projects an oval of light which ravels slowly on the boxes of the cupola, adding to the magic of the place.

Outside, the upper part of the cupola was covered of gilded bronze tiles.

The structure of the building

The internal structure of central construction (rotunda and cupola) must resist several types of constraints:

to resist the top of the vault to the forces of vertical depression,
to compensate for the forces of spacing at the base of the cupola
to allow the circular wall to support the weight of the cupola

The Roman manufacturers solved these problems by two methods.

the choice of the construction materials :
L' large-scale use of the Concrete (Opus caementicium), cast between Facing S of bricks (Opus latericium), transforms the building into a coherent block, whose rigidity ensures a good resistance to the forces of deformation quoted above. According to the level of the building, this concrete includes a different Granulat, adapted to the needs for resistance or lightness. On the basis of the foot of the building, one finds successively the concretes following:

wall of rotunda, until the first external Cornice: concrete with glares of Tuff and Travertine
wall of rotunda, between the first and second cornices: concrete of tuff and bricks
first ring of the cupola and wall external with the top of the second cornice: crushed brick concrete (mortar with the Broken tile)
second ring of the cupola: concrete of tuff and crushed bricks
cap of the cupola: concrete reduced with a aggregate of Pumice and tuff, in decreasing thickness passing 5,90 m at the base to 1,5 m on the level of the oculus, covered with a coating of sealing of 15 cm, it tends to be calcified always more into growing old, which ensures to him an excellent behavior with the wire of the centuries. Thus run, the cupola constitutes a cast solid dome, which one calls a vault concretes, adjective derived from the word “concretion” (of the mortar).

the reorientation of thorough the The constraints of statics are double: the base of the cupola (4) tends to push the wall which supports it towards outside, and this wall which constitutes the interior of the rotunda (2) is not full, it is hollowed out by the seven exèdres (3) and by the entry of the temple, and a row of empty sections at the higher level. The weight of the cupola is thus supported by the eight solid masses pillars of masonry which separate these intervals. It is thus necessary at the same time to compensate for centrifugal pushes, and to direct the vertical pushes towards the eight pillars. The Roman builders implemented several solutions:

a rise in 8,40 m of the wall external (1) of the rotunda exceeds the foot of the cupola and acts against a Contrefort (5).
the base of the cupola is overloaded by a series of seven rings of concrete superimposed in staircase (6), visible of outside, which by a vertical push redirect the centrifugal lateral thrusts
inclusion in the thickness of the cupola large arches relieving out of bricks, to direct the pushes on the pillars of the rotunda. Other brick arcs are included in the wall of the rotunda (visible of outside) return the pushes towards the pillars.
reinforcement of the part carrying the interior wall of the rotunda by a series small radial arcs between the interior wall and the wall external of the higher level

Gallery , while building on clotheshangers assembled with Beam S and covered with reeds. Here the range imposed on the clotheshangers is important, (43 meters), but it is known that the Basilique S Romans were covered with frames, with principal rafters from 25 to 30 m of range, width observed on the vestiges. One can thus admit the assumption suggested in Gründ of a formwork supported by a clotheshanger out of frame taking support on the interior cornices of the rotunda. The process thus described is economic, because it requires only one bending of rather light wood time to build the first thickness, bending charge carrier complete being made up by the first thickness of the vault.

For memory, let us quote also an alternative solution suggested by Pierre Gros: to fill ground or sand the rotunda, to case over, build the cupola, then to empty the rotunda. This very simple technique is like the preceding one with the range of the Roman builders, who showed with the Mausolée of Auguste their capacity to mount and fill with ground a large cylindrical building.

Transformations with the wire of time

Roman period

Documents quote a restoration under Antonin the Piles, and an inscription on the architrave records another restoration under Septime Sévère in 202.

Being dedicated to all the gods, the Pantheon could have developed the reception of additional divinities. It does not seem to have been the case: no documentary source indicates that one of the successors of Hadrian did not add any divinity to the Pantheon, in spite of the occasions which our modern idea of a syncretism interfered oecumenism suggests: Hadrian divinized into 138 could have had his worship in the Pantheon, it had his particular temple, whose wall remains, integrated in the building of the Stock Exchange. Later, Héliogabale, which wanted to install Baal in Rome, preferred to build a new temple to him. Alexandre Sévère, with the religious direction considered syncretic, sheltered its collection of hero and divinities in a personal Laraire. Lastly, when Aurélien officialized the worship of Sol invictus, it also made him build a new temple.

The Pantheon had to know the vicissitudes which struck all the ancient temples of Rome at the end of the 4th century: prohibition of sacrifice and frequentation of the temples in 391, transitory resumption of the traditional ceremonies in 393 at the time of the usurpation of Eugene, prohibition by Théodose I {{er}} of any form of pagan activity in 392 which is essential on Rome with the defeat of Eugene.

The many bronze statues and decorations on the pediment of the Pantheon were perhaps victims of recoveries at the time of the head office of Rome by Alaric in 408, during which the ornaments of the temples were taken to pay the ransom required by Alaric, or were plundered during the Sac of Rome of 410 or that of 455.

The Middle Ages

The Byzantine took again the control of Rome at the 6th century. Obviously the Pantheon, formerly public monument, remained imperial property, since in 609, the Byzantine emperor Phocas made of it gift with the Pape Boniface IV. This one devoted it like Christian church to the Virgin Mary and the Martyr S ( Sancta Maria AD Martyrdoms , i.e. Sainte-Marie with the Martyrs), title which it carries still nowadays. It made transfer from the anonymous remainders taken in the Catacombes and install a furnace bridge on these relics. With the eyes of a former Roman, if it had appeared strange to admit the practitioners in the concealed, instead of celebrating the worship with open sky in front of the temple, the burial of human skins in the temple was a sacrilege: any burial was banished not only in the surface of the temple, but also in the crowned space (Pomœrium) of Rome. The installation of the relics in the Pantheon is a sign more among others of the disappearance of this taboo than thousand-year-old. Nevertheless, one notes the power of the architectural principles of the Pantheon, whose axial symmetry imposed the placement of the furnace bridge in the southern exèdre, vis-a-vis the entry, and not in the east according to the Christian use. The dedication of the building saved it vandalism and deliberated destruction which ruined the majority of the monuments of the ancient Rome during bottom Moyen-âge.

In 663, the Byzantine emperor Constant II (641-668) which conducted campaign against Lombards in Italy of the south briefly remained in Rome. With court of finances, it made recover the gilded bronze tiles which covered the cupola of the Pantheon. A lead cover replaced them in 735.

The Marbre S interiors and the large gate in Bronze survived, even if this last were restored on several occasions as in 1563. The persons in charge of this plundering were scoffed by this epigram “ Quod not fecerunt Barbari, fecerunt Barberini ” (what the Barbarians did not do, Barberini one makes).

Lastly, in 1747, the architect and painter baroque Luigi Vanvitelli restored the interior decoration of the rotunda, occulting the windows which were under the cupola by replacing them by blind windows., its pupils Baldassarre Peruzzi (1481-1536) and Perin del Vaga (1501-1547), then the painters Giovanni da Udine (1487-1564), Taddeo Zuccaro (1529-1566) and Annibale Carracci (1560-1609), the heart of the diplomatic cardinal Ercole Consalvi (death in 1824) and two kings d' Italie: Victor Emmanuel II (death in 1878) and Umberto Ier (death in 1900), as well as the wife of this last, the queen Marguerite of Savoy (dead in 1926)

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