in historical context
Roman Imperial Architecture
As so often in late antiquity the imperial residence was accompanied by a circus, which is estimated as having held about 15,000 spectators, and which offers an unusually detailed picture of one of the racecourses that played such a large part in the social, and frequently also the political, life of later antiquity. The architectural niceties were many. Here one can see, for example, the ingenious irregularities of plan which ensured a fair start for the competitors in the outer lines; the starting-gates (carceres) set between the traditional pair of flanking towers (oppida); the two turning-points (metae) at either end of the central barrier (spina), which was placed well off-axis so as to allow for the crowding of the initial lap; the imperial box, overlooking the finishing line, and a second box near the middle of the opposite side for the use of the judges and organizing officials; the entrances and exits for the ceremonial parades of the contestants; and on the central point of the spina, in imitation of the Augustan obelisk in the Circus Maximus, the site of the Egyptian obelisk which Maxentius brought from Domitian's Temple of Isis in the Campus Martius and which Innocent X in 1651 retransported to the city to adorn Bernini's fountain in the Piazza Navona [which was the Circus of Domitian, also in the Campus Martius]. Constructionally the building is of interest for its bold use of alternative courses of bricks and of small tufa blocks, and for the large hallow jars used to lighten the mass of the vaulting that carried the seating, both characteristically late features which are discussed in greater detail later in this chapter.
John Bryan Ward-Perkins, Roman Imperial Architecture (New York: Penguin Books, 1981), pp. 421-424.
The circus of Eutropia's bastard son; a lost Piranesi found.
Re: FW Evolutionary theory and architecture
Aside from strictly religious (temple and church) architecture, the case can be made that classical Roman architecture, in general, reached its climax during the reign of Maxentius, and ended 28 October 312, when Maxentius lost his life in battle with Constantine at the Milvian Bridge--Maxentius became (usurpative) emperor of Italy and North Africa 28 October 306, and Constantine attributes his Christian conversion to events that occurred the eve of 28 October 312. The architecture built in Rome under Maxentius is of the utmost refinement, e.g., the Circus of Maxentius manifests the most precisely designed of all Roman circuses. [Incidentally, the Circus of Maxentius plays a key role in the manifestation of two Ichnographia Campus Martius.] Records indicate that it may have been only a month after Constantine's triumph at the Milvian Bridge that the first Christian Basilica in Rome, first named after Constantine and today St. John Lateran, began construction. The architecture of Rome executed under Constantine (312-330) further includes (at least), St. Peter's at the Vatican, separate Basilicas of St. Lawrence, Agnes, and Peter et Marcellinus, Santa Croce in Gerusalemme (which is all that remains today of Elegabalus' Sessorian Palace, where Helena took up subsequent residence in Rome), the Arch of Constantine (which reused pieces of the Arch of Trajan), the Baths of Constantine, the Baths of Helena, and the Mausoleum of Helena (whose ruins exhibit construction very similar to the ruins of the great Constantinian Bath of Treves (Trier, 306-312), which were the largest Roman Baths outside Rome).
can you spot the differences?
Each of the six circuses delineated within the Ichnographia (large plan) were completely changed in design configuration to the perfected configuration that is found in the real Circus of Maxentius (306-312 AD). Piranesi's own circus designs (i.e., with the openings) in the first state are very stylized versions of a circus plan.
Piranesi spent a lot of time surveying and measuring Roman ruins, and perhaps he himself measured the Circus of Maxentius, found the refinement of its plan (apparently the Circus of Maxentius is the most refined arena layout for chariot racing), and thought to change his circus designs after some printings of the Ichnographia were already published (--but here I'm only making a possible guess).
Re: Virtual and Real
So what is Quondam going to be like as it travels around the Sun for an eighth time? Well, for sure there will be work done of The Architecture of Maxentius or The Last Great Pagan Architecture of Rome. This is the fist part of "Eutropian Theories" the final chapter of EPICENTRAL. Eutropia was the mother of Maxentius, but soon after his death (28 October 312, the day after the night Constantine said he converted to Christianity--Maxentius died in battle with Constantine), Eutropia confessed that Maxentius was a bastard, thus not the legitimate heir of the Emperor Maximian. [I guess you have to know the whole history to get the joke, but wouldn't be interesting and funny if Maxentius was actually the son of Diocletian?] Anyway, there is no question that the mother of the emperor under whose rule the great dual Temple of Venus and Mars was built in the Roman Forum is the same person who later initiated the building of the first Christian basilica at Hebron.
Re: NeoClassical Chili
Krautheimer published an essay--"Mensa-Coemeterium-Martyrium" 1960--where he earnestly speculates about the very real possibility that the early "Constantinian" basilicas (aside from St. John Lateran and St. Peter's Vatican) acted as covered graveyards where funeral banquets were held. He also noted how the shape of these basilicas was circus-like. When I read this essay (early 2005), I immediately though of the connection to the 'munus' ritual as related by Tertullian. And, after finding out more about the Mausoleum of Romulus/Circus of Maxentius complex (also early 2005), the "pieces" quickly fell together, particularly the connection of Eutropia to all this.
The Circus of Maxentius has been a unanswered question in my mind for a few years now, and now I think I know why Piranesi 'secretly' printed two different version of the Ichnographia Campus Martius--the Circus of Maxentius is the 'key' to the inversion of the pagan Roman Circus into the Early Christian 'basilica'. Piranesi, in La Anticita Romane II (which predates the Campo Marzio publication by four years or so), delineated a "reconstruction" of the Basilica of St. Agnes--q1580-compare this with a present aerial view--q3062 .
Scan/dxf of Basilica Marcellus & Peter, Circus of Maxentius, Circus Varianus/Santa Croce, Basilica at Santa Costanza, Basilica of St. Laurence, Basilica of St. Sebastian. So far just seeing the plans at the same scale relative to each other and relative to plans of other 4th century/Constantinian buildings has made the effort worthwhile