In the late fifteenth century, a young Roman boy stumbled into a fissure in the side of the Aventine hill in Rome and found an underground grotto with ornately painted stucco walls [fig. 1].1 These decorated underground corridors were the remains of the Domus Aurea, the emperor Nero's infamous golden pleasure palace, which was demolished and converted into the Baths of Trajan and the Colosseum after Nero's death in AD 68. His accidental discovery sent a wave of excitement through the Roman art world, which was just entering the Renaissance. Artists such as Raphael, Giovanni da Udine, and Michelangelo visited the subterranean chambers. The frescoes, with their delicate colors and intricate motifs, inspired Raphael in his painting of the Loggetta of the Vatican [fig. 2].2 This rediscovery of the art and architecture of antiquity inspired a new generation of artists and renewed the public's fascination with the Domus Aurea.
The construction of the Domus Aurea proceeded in two stages, the Domus Transitoria ("House of Passage") and the Domus Aurea ("House of Gold"), punctuated by a great fire that destroyed much of Rome [fig. 3]. When the fire damaged the Domus Transitoria, Nero capitalized on the destruction of Rome to annex certain properties and begin construction on the second phase of the Domus Aurea, which lasted until Nero's forced suicide in AD 68. For many, the Domus Aurea was the visual symbol for all of Nero's excesses and injustices. Vespasian's deliberate demolition of the Domus Aurea, Nero's private pleasure house, to build an entertainment venue for the masses, attests to the power of this symbol. This gigantic amphitheater became known as the Colosseum, after Nero's Colossus statue that stood nearby. The Domus Aurea, one of Rome's most hated buildings, built by one of Rome's most hated emperors, nevertheless had a significant influence on the future course of Roman architecture. Although it showcases the first known use of groin vaults and vault haunch clerestory windows in Roman concrete architecture, this building's importance does not lie in any specific architectural innovation; rather, it was part of the "concrete revolution" that introduced a new era in Roman architecture through the sheer daring of some of its features and the confidence that the architects showed in their medium. The Domus Aurea helped Roman architecture to break from its Hellenistic trabeate traditions, with straight, horizontal beams and lintels, and become more curving and arcuate.3
The creator of the Domus Aurea, the emperor Nero (AD 37- 68), is one of the most infamous historical figures of all time. His list of crimes is lengthy and notorious: he poisoned his stepbrother Britannicus, he had incestuous relations with his mother Agrippina and after several attempts succeeded in murdering her, he kicked his wife Poppaea to death when she was pregnant, he married the freedman Pythagoras and dressed the boy Sporus in the clothes of an empress, he set fire to Rome in order to proceed with his building plans and fiddled as it burned, and most egregiously, he built an enormous golden palace in the center of Rome that was for many the symbol of his extravagance and detachment from reality.4 Nero's reign was a Golden Age, because the emperor was obsessed with obtaining gold, surrounding himself with a variety of golden objects ranging from a golden poison box to a golden chamber pot.5 The House of Gold that Nero built may have been literally coated with gold and rich materials: as Suetonius describes, “Parts of the house were overlaid with gold and studded with precious stones and mother-of-pearl.”6 Gold also had an ideological significance for Nero, because gold was associated with the golden-haired Apollo and the golden Sun, the source of good things. He was particularly concerned to identify himself with the Sol aspect of the god Apollo.7 However, none of the primary sources about the Domus Aurea describe it as a palace of the sun, either to praise or condemn it. The Roman public did not interpret the building in a religious way, which is reasonable, considering that Nero did not have strong religious convictions himself; instead, they viewed it as a private luxury palace.8
The stories about Nero’s life come from two main ancient sources, each with a distinctly anti-Neronian bias. The historian Publius Cornelius Tacitus (c. AD 56- after c. 120) wrote about the Julio-Claudians in the Annals, a history of Rome from Augustus to Nero; he was about twelve or thirteen years old when Nero committed suicide. The biographer Gaius Suetonius Tranquillus (c. AD 70- c. 130), who was born after Nero’s death, wrote the Lives of the Twelve Caesars, a vivid account of the characters of the Julio-Claudian family. Scholars agree that these writers worked independently from earlier literary and oral historical sources, although they must have been aware of each other’s work.9 This confirms the legitimacy of their facts, but they presented those facts in an inflammatory, accusatory way that may obscure some of Nero's achievements in architecture. Nero, who was very passionate about the arts and considered himself a fine singer and actor, was an excellent judge of creative talent, and he challenged his architects to create the most imaginative palace in Roman history.10
Suetonius states that Nero “built a palace, stretching from the Palatine to the Esquiline, which he called 'The Passageway'; and when it burned down soon afterwards, rebuilt it under the new name of 'The Golden House.’”11 All of the ancient sources are in agreement about the two-stage chronology of the Domus Aurea; although Nero never intended to have two specific phases in building his palace, the fire of Rome necessitated a fresh start.12 Nero initially commissioned the building around AD 60 as a convenient passageway from the Domus Tiberiana, his splendid Palatine hill residence, to the gardens of Maecenas on the Esquiline, a couple of miles away [fig. 4]. In this stage, it was known as the Domus Transitoria. Less is known about the Domus Transitoria than the latter stages of the Domus Aurea, because no literary source describes the architectural features of the Domus Transitoria; also, much of the structure was destroyed in the fire of Rome, and the remaining architecture was incorporated into the foundations of the Domus Aurea.13
Before Nero began his immense building project, the valley between the Palatine and Esquiline hills had been urbanized for quite some time, since the middle of the Republican period. Although the physical features of the environment made it difficult to build in the valley, its importance in the urban environment ensured that it was filled with "public, sacred, and residential buildings."14 According to Larry Ball, Nero was not content to stay within the limits defined by the existing buildings around the Domus Transitoria, so he acquired the properties around his building "by fair means or foul" and destroyed the structures on them to make room for his passageway.15
Nero may have found a way to clear most of the city of Rome for his building projects. Between July 18th and 19th in AD 64, a great blaze destroyed much of the city of Rome and damaged the Domus Transitoria. Ball states that because of its location, the Esquiline part of the Domus Transitoria was probably more damaged by fire than the Palatine section.16 Out of the city's original fourteen districts, four were left unburned. The fire began in some shops between Palatine hill and Caelian hill and quickly grew to envelop the entire circus, then spread into the hills. Most primary sources dealing with the fire of AD 64 implicate the Emperor Nero. Suetonius states that Nero “brazenly set fire to the city,” ordering his attendants to burn anything flammable and using siege-engines to knock down stone buildings that lay in the path of his building plans.17 Tacitus is more cautious: “whether [the fire was] accidental or treacherously contrived by the emperor, is uncertain, as authors have given both accounts.”18
Historians are divided as to Nero's complicity in the fire and its aftermath. Ball suggests that Nero used siege-engines siege- engines to clear away the wreckage of damaged buildings rather than to demolish intact buildings,19 whereas Coarelli et. al. state that the evidence for a multitude of buildings in the area prior to the fire "fully confirms all accounts from ancient sources” that Nero destroyed extant buildings with siege-engines.20 Nero himself was in Antium at the time, and according to Tacitus “he did not return to Rome until the fire approached his house [the Domus Transitoria], which he had built to connect the palace with the gardens of Maecenas," but he could have ordered his men to set fire to the city or keep it burning, as Tacitus suggests.21 Whether he was responsible for the great fire of Rome or not, Nero soon “availed himself of his country's desolation” to work on his new project: the Domus Aurea, the grandest building the city had seen.22
Two architects worked on the palace: as Tacitus states, “the directors and contrivers of the work were Severus and Celer, who had the genius and the audacity to attempt by art even what nature had refused.”23 Their style is characterized by the incorporation of existing structures into their building project and the creative use of space. Severus and Celer did not build any new structures unnecessarily, reusing retaining walls or the foundations of earlier buildings rather than replacing them with new structures.24 Instead of approaching the building as a set of structures, they created a series of voids, made possible by the use of concrete architecture, which appeared in Rome around the third century BC.25 As Ball characterizes it, the Domus Aurea was designed as a set of interior spaces encased in solid concrete, with the actual walls subordinate to the space they enclosed.26
There were two basic structures associated with the Domus Aurea: the Palatine wing and the better-preserved Esquiline wing. Given its proximity to the forum, the Palatine wing probably served Nero as a townhouse, the center of his administrative and public activities. It may have been designed like a Hellenistic palace, inspired by "the grand, royal palaces of the Hellenistic world, especially the palace of the Ptolemies in Alexandria, with its pavilions set in a huge park and its zoo.”27 The scanty archaeological evidence about the Palatine wing shows that it had a large, square platform with a smaller square-shaped central building with cryptoportici (supporting corridors) underneath it on three sides. These features are consistent with a Hellenistic palace style, but not conclusive.28 Ball argues that the more isolated Esquiline wing, surrounded by parkland, was more of a luxury suburban villa where Nero could relax like other Roman elites. The Esquiline wing is the main source of information about the Domus Aurea today, because it is the best-preserved structure.29 Many scholars use what they know about the Esquiline wing to generalize about the Palatine wing, which may be problematic given the differences between the buildings.
The Neronian masonry in the Domus Aurea was opus testaceum, a facing of long, slender bricks over opus caemeticium, Roman concrete.30 After carefully analyzing the sequence of masonry types in the Esquiline wing, Larry Ball concluded that there were four phases of masonry in the Domus Aurea up to Nero's time. The first two phases were from buildings demolished before Nero's building project, and show that Severus and Celer reused earlier buildings in important ways in the South and Southwest groups of the Pentagonal Court and certain other corridors. The third and fourth phases represent the two phases of the Domus Aurea. As Ball states, the masonry for the Domus Transitoria was carefully constructed and consistently used according to an overarching design, and is found in the west section of the Esquiline wing. The masonry used in the Domus Aurea was “slightly coarser, with marginally fatter bricks and a bit less carefully assembled.”31 The masonry evidence shows that the foundations of the project and even whole rooms were reused from earlier buildings, and that the western portions of the Esquiline wing were reused from the Domus Transitoria, while the eastern portions of the Esquiline wing were created from scratch.32
The walls of the Domus Aurea were decorated with elaborate yet delicate Pompeian
Fourth style painted frescoes [fig. 1]. According to Nancy and Andrew Ramage, several scholars have suggested that the painter who worked in the Domus Aurea, Famulus, also known as Fabullus, was at least partially responsible for inventing the Fourth style.33 The Fourth style used in the Domus Aurea featured a creamy background color with Third style decoration predominating over the occasional small illusionistic scene. The decorative motifs used, such as the “candelabra, small pinakes [painted panels], festoons, reedlike columns, etc.,” are characteristic of Third style painting as well.34 Many rooms had a lower panel, known as a dado, with yellow-ground frescoes with red designs. The decorations often served to link related groups of rooms together, with consistent color schemes and motifs. Today, these frescoes are in relatively poor condition partly because of their exposure to the elements since their discovery in the fifteenth century.35
According to Boëthius, axial symmetry became an important element in Roman architecture over time.36 At first glance, the extant Esquiline wing does not appear to have axial symmetry; although it is divided into west and east sections with a pentagonal court between them, these sections do not have equal weight or similar shapes [fig. 5]. However, the Esquiline wing features groups of rooms known as suites that were thematically and probably functionally related, and which taken together create axially symmetrical vistas. Thus, the Domus Aurea shows a typically Roman regularity and systemization, even if it is not as symmetrical as a whole as most other Roman buildings. In the Esquiline wing, several suites are worthy of note, including the Nymphaeum Suite in the west section and the famous Octagon Suite, the focus of the east section.
The Nymphaeum Suite was the second most important group of rooms in the Esquiline wing, behind the Octagon Suite. The architecture of the suite, based on the Roman prototypes of the atrium house and the luxury villa, suggests that it was a residential area, which Nero used either as a home away from his Palatine home or as a guest house when he entertained friends.37 It featured a variety of waterworks, including a cascading waterfall and a pool with a fountain in the eastern room on the central axis of the suite. The Nymphaeum Suite was first built in the Domus Transitoria phase of the palace in traditional trabeate style, with a central compluvium letting light into the room and allowing water to fall into the impluvium [fig. 6]. When Severus and Celer returned to the structure to incorporate it into the Domus Aurea, they reconfigured the ceiling, replacing the flat ceiling with a barrel vault and creating the “vault haunch clerestory window,” a new structure in Roman architecture [fig. 7].38 This new form may have developed by accident in the course of remodeling, when Severus and Celer cut windows through a solid wall to create a new light source to replace the compluvium they had recently blocked.39 Whereas in the compluvium system, the light entered the room through a simple skylight, the vault haunch clerestory windows obscured the light source, making the lighting mysterious and diffuse.40 Unlike a true clerestory, the vault haunch clerestory does not project upwards into the piano nobile, making it useful in architecture.41
The finest expression of Severus and Celer's innovations in the Domus Aurea is the
Octagonal Suite in the eastern part of the Equiline Wing [fig. 8- 10]. It was carefully designed and carried out exactly according to plan, with no changes during construction. A stepped artificial waterfall carried water down to the rear of the room.42 The octagon room rose from an eight-sided base with pilasters on the corners to a domed concrete ceiling covered with blue, teal, and white glass mosaics with a central oculus.43 Concrete allowed the octagonal base to blend smoothly into the rounded dome. The extrados of the dome featured struts that became successively thinner near the top of the dome as the load became lighter. This allowed the maximum space for vault haunch clerestory windows between the struts. These clerestory windows are similar to the ones used in the Nymphaeum Suite; Ball suggests that Severus and Celer perfected their motif in the octagon room.44 The groin vaults used in the octagon room are both structurally complex and unnecessary, because transverse barrel vaults would have performed the same task, supporting the room without obscuring the lighting. Ball took this to mean that Severus and Celer had used this architectural motif before, in a building that has been lost, which allowed them to become confident in the design of the motif and so enamored of it that they used it purely for aesthetic appearance in the octagon room.45
The only room that Suetonius describes in any detail is a round dining room, known as the cenatio rotunda, with a variety of technical features: "The main dining-room was circular, and its roof revolved, day and night, in time with the sky.”46 Many scholars have assumed that this room in some way represented the heavens because of Suetonius' description: some have stated that it was painted with stars like a planetarium, while other have compared it to the daily movements of the sun, but Suetonius may not have been speaking literally when he compared the room's movement to the sky.47 So far, no room in the Domus Aurea has been found with mechanisms to allow it to rotate, but scholars believe that this revolving round room is “beyond suspicion of being a literary fantasy.”48 It may have been in a separate, small building somewhere on the palace grounds, or it may have been that only part of the room, such as the ceiling or floor, rotated. In that case, it could be the same room as the octagon room described above. Boethius describes several theories about the mechanism to turn the cenatio: it may have been powered by animals or “water power such as that of the cascade in the Octagon.”49 Wherever this dining room was, if it existed in the form that Suetonius describes, it must have been unbelievably luxurious: “All the dining-rooms had ceilings of fretted ivory, the panels of which could slide back and let a rain of flowers, or of perfume from hidden sprinklers, shower upon his guests.”50
In addition to the buildings on the Palatine and Esquiline hills, the landscaped grounds surrounding the Domus Aurea were an intrinsic part of its design. Nero's alterations to the valley were extensive, including raising the ground level four meters after the fire in order to build the Domus Aurea.51 In Nero's grand mansion, “the jewels and gold, long familiar objects, quite vulgarised by our extravagance, were not so marvelous as the fields and lakes, with woods on one side to resemble a wilderness, and, on the other, open spaces and extensive views.”52 Many of the rooms were designed around specific vistas, and the landscape was carefully shaped to provide pleasing views. Nero created a large lake basin that was four to six meters deep in the middle of the valley. Gabucci states that according to recent estimations, this lake could hold 122,000-183,000 cubic meters of water, and it took several days to fill it with water from the Claudian aqueduct.53 This pool, or stagnum, was the focal point of Nero's palace, bordered by buildings alternating with open grassy areas to create the illusion of a world in miniature. As Suetonius describes: “An enormous pool, like a sea, was surrounded by buildings made to resemble cities, and by a landscape garden consisting of ploughed fields, vineyards, pastures, and woodlands- where every variety of domestic and wild animal roamed about.”54 According to Champlin, the central pool may have represented the Mediterranean Sea, surrounded by the dominions of the Roman Empire, so that Nero could survey his possessions from the comfort of his own home.55
In keeping with his public identification with Sol, Nero commissioned an immense statue of the Sun in bronze to decorate the vestibule of his Domus Aurea. Traditional belief holds that this Colossus was intended as a portrait of the emperor, later reworked into a generic image of the Sun. Suetonius illustrates the size of the Domus Aurea by stating, “The entrance-hall was large enough to contain a huge statue of himself [Nero], 120 feet high; and the pillared arcade ran for a whole mile.”56 Champlin states that there is no evidence that the statue, which lasted into the fourth century, bore the features of Nero.57 Scholars have tried to reconcile the assertions of ancient sources such as Suetonius and Pliny that the statue was a portrait of Nero with the later observation that the Colossus did not resemble Nero by claiming that Vespasian had the face altered to look more like a traditional Sol. This claim is based on Suetonius’s statement that Vespasian gave rich gifts to the one who “restored” the Colossus, although this could simply mean that Vespasian had the statue finished.58 Vespasian followed a policy of obliterating the signs of Nero’s activity during his reign, so if the statue did originally represent Nero, he would have transformed it into a statue of Sol.
According to Suetonius, Nero dedicated the Domus Aurea with the words, "Good, now I can at last begin to live like a human being!"59 However, the Roman people were less excited about the emperor's extravagant new palace. The public reaction to Nero’s building project was swift and hostile. Suetonius states that the palace was the finest example of Nero's wastefulness;60 however, the worst aspect of the building in the public mind was not the luxury of its construction materials, but its sheer size and central location in the heart of Rome. Tacitus implies that little of Rome “was left unoccupied by his mansion.”61 Suetonius also describes an anonymous verse that was either written on a wall or circulated verbally throughout Rome: "The Palace is spreading and swallowing Rome! Let us all flee to Veii and make it our home. Yet the Palace is growing so damnably fast, that it threatens to gobble up Veii at last."62
The Domus Aurea lasted only four years, between the fire in AD 64 and Nero's suicide in AD 68, and it was not completed before his death. After Nero died, the emperor Vespasian, a former soldier of modest equestrian origins, took the throne. To legitimize his rule over Rome, he sought to show the public that he was a man of the people with Republican values by destroying the Domus Aurea.63 He gave the land that Nero's golden palace had occupied back to the people by constructing a huge public amphitheater for their entertainment. He conceived a plan for remodeling the valley that was carried out by his sons, Titus and Domitian, and his alterations were to last longer than Nero's.64 In little more than a decade, he had drained Nero's lake and raised the valley floor two meters in order to build the Flavian Amphitheater, which became known as the Colosseum because of the proximity of Nero's colossal Sol statue.65 He covered the ruins of the building with a platform of travertine blocks 17 1/2 meters wide surrounding the Colosseum,66 and he converted the parks around the Domus Aurea into public entertainment grounds.67 Vespasian understood the Roman public's powerful hatred of the Domus Aurea and the extent to which they identified it with emperor Nero himself, and by destroying the palace, he also broke with the Julio-Claudian past to establish his own dynasty, the Flavians.
Although brief-lived, the Domus Aurea was one of the most infamous, hated buildings of all time because of the corruption and vice of the man who commissioned it. Despite its negative reputation, it had a powerful influence on future Roman art and architecture. The most revolutionary aspect of the Domus Aurea was the way in which Severus and Celer constructed it, using concrete to create forms that were exciting and new. The architects understood the concrete medium and its possibilities and limitations, which allowed them to design freely. Severus and Celer created some architectural forms that were new to Roman architecture, such as the groin vault and vault haunch clerestory window, and advanced the progress that Roman architecture was beginning to make in freeing itself from the limits of the trabeated architecture of the Hellenic world.
Anderson, James C., Jr. "The Date of the Thermae Traiani and the Topography of the Oppius Mons." American Journal of Archaeology (1985): 499-509.
Ball, Larry F. The Domus Aurea and the Roman Architectural Revolution. Cambridge, UK: Cambridge University Press, 2003.
Boëthius, Axel. The Golden House of Nero: Some Aspects of Roman Architecture. Ann Arbor, MI: The University of Michigan Press, 1960.
Champlin, Edward. Nero. Cambridge, MA; London: The Belknap Press of Harvard University Press, 2003.
Coarelli, Filippo, Gian Luca Gregori, Leonardo Lombardi, Silvia Orlandi, Rossella Rea, and Cinzia Vismara. The Colosseum, ed. Ada Gabucci, trans. Mary Becker. Los Angeles, CA: J. Paul Getty Museum, 2001.
DeLaine, Janet. "Structural Experimentation: The Lintel Arch, Corbel and Tie in Western Roman Architecture." World Archaeology (1990): 407-424.
Quennell, Peter. The Colosseum. New York: Newsweek Book Division, 1971.
Ramage, Nancy and Andrew Ramage. Roman Art, 4th ed. Upper Saddle, New Jersey: Pearson Prentice Hall, 2005.
Tacitus, Publius Cornelius. The Annals and the Histories, vol. 15, Great Books of the Western World, ed. Robert Maynard Hutchins. Chicago, IL: Encyclopedia Britannica, 1952.
Tranquillus, Gaius Suetonius. The Twelve Caesars, ed. Michael Grant, trans. Robert Graves. London: Penguin Books, 1957.
1Peter Quennell, The Colosseum (New York: Newsweek Book Division, 1971), 16.
2Nancy Ramage and Andrew Ramage, Roman Art, 4th ed. (Upper Saddle, New Jersey: Pearson Prentice Hall, 2005), 155.
3Larry Ball, The Domus Aurea and the Roman Architectural Revolution (Cambridge, UK: Cambridge University Press, 2003), 25.
4Derived from Gaius Suetonius Tranquillus, The Twelve Caesars, ed. Michael Grant, trans. Robert Graves (London: Penguin Books, 1957).
8Axel Boëthius, The Golden House of Nero: Some Aspects of Roman Architecture (Ann Arbor, MI: The University of Michigan Press, 1960) 126.
9Edward Champlin, Nero (Cambridge, MA; London: The Belknap Press of Harvard University Press, 2003), 37-39.
14Filippo Coarelli, Gian Luca Gregori, Leonardo Lombardi, Silvia Orlandi, Rossella Rea, and Cinzia Vismara The Colosseum, ed. Ada Gabucci, trans. Mary Becker (Los Angeles, CA: J. Paul Getty Museum, 2001), 163.
18Publius Cornelius Tacitus, The Annals and the Histories, vol. 15 of Great Books of the Western World, ed. Robert Maynard Hutchins (Chicago, IL: Encyclopedia Britannica, 1952), 166.
20Coarelli et. al., 9.
27Coarelli et. al., 9.
33Ramage and Ramage, 93.
45Ball, 229, 256.
48K. Lehmann, “The Dome of Heaven,” Art B., XXVII (1945), 19 ff.; quoted in Boëthius, 121.
51Coarelli et. al., 161.
53Coarelli et. al., 163.
63Coarelli et. al., 10.
64Coarelli et. al., 164.
65Coarelli et. al., 161.
66Coarelli et. al., 164.
67James C. Anderson, Jr., "The Date of the Thermae Traiani and the Topography of the Oppius Mons," American Journal of Archaeology (1985), 501.