At the end of the Ist century A.D., the valley of the Imperial Fora was completely occupied by four forums that up to that point had been built there. In chronological order they were: the Forum of Caesar (46 B.C.), the Forum of Augustus (2 B.C.), the Forum of Peace (75 A.D.) and the Forum of Nerva (97 A.D.), the later at the behest and in large part built by the emperor Domitian (81-97 A.D.).

The excavation of the slopes of the Quirinal Hill

It is quite probable that it was also the emperor Domitian who began the work of excavating the slopes of the Quirinal hill that closed the Valley of the Imperial Fora to the north, in an effort to acquire space for new buildings and perhaps an additional forum. The enterprise was undertaken and although it is not known precisely how long it took to be completed, the works were carried out in the period between 95-105 A.D., thus in the last years of Domitian’s reign and the early years of that of Trajan (98-117 A.D.). It is calculated that 300,000 cubic metres of volcanic tuff rock were removed, thus creating an area of approximately 4.2 hectares (10.4 acres) available for new buildings. It was in this area that the fifth, final and most impressive of the Imperial Forums was built: the Trajan’s Forum.

Why another Forum?

The construction of this new forum was probably motivated by the need to increase the space dedicated to the administration of justice. The courts which previously had been housed in the Roman Forum had been moved to the Forum of Caesar and then chiefly to the Forum of Augustus. At the same time, the new Forum was built to celebrate the Roman victory over the Dacian people whom Emperor Trajan had defeated in two arduous military campaigns, the first between 101-102 A.D. and the second between 105-106 A.D. The Dacians inhabited a vast area which corresponds roughly to the area of modern-day Romania which once conquered was transformed into the Roman province of Dacia. The extraordinary spoils of war greatly enriched the Empire and were used to build the Forum which was inaugurated in 112 A.D.

The architecture of the Forum

The complex was made up of a large rectangular square 110×85 metres, flanked by deep columned porticoes on the two long sides, closed to the south by a set of huge columns of coloured marble and to the north by the facade of the Basilica Ulpia, an imposing structure of two storeys and five aisles. Beyond the Basilica to the north was a quadrangular shaped courtyard. Overlooking it were two rooms that faced each other and which housed two separate libraries. At the centre of the courtyard was Trajan’s Column. Closing the courtyard was a pronaos with columns whose shafts were 15 metres high (there are no larger columns known to have existed in the entire Roman Empire) which served as the entrance to the Forum from the north.

The Porticoed Court to the South

Access from the south was through a monumental courtyard that was 25×27 metres, with columns on three sides, decorated with coloured marble and positioned between the Forum of Augustus and the southern end of the Forum of Trajan. The remains of this structure came to light during the excavations of 1998-2000.

Trajan’s Column

The military campaigns against the Dacians were recounted in the long relief that spiralled up Trajan’s Column, one of the most extraordinary works of Roman art of all times. Inaugurated in 113 A.D., it was topped by a golden statue of the emperor, and his name was carved in the inscription at the base which commemorated the excavation of the slopes of the Quirinal hill (referred to here as ‘mons‘, or ‘mount’). Tradition has it that inside the base of the Column were two golden urns that held the ashes of Trajan and of his wife Plotina, which over time were lost. None of the other emperors were buried within their own Forum, nor even within the pomerium, which was the sacred confines of the City, inside of which it was forbidden to bury the dead. This is another of the exceptional features of Trajan’s Forum, perhaps the most extraordinary of all.

The temple that isn’t there

Within Trajan’s Forum there is no temple, a building which is present in all the other Imperial Fora. In the past it was believed that an enormous temple had been built to celebrate the deified Trajan and Plotina (and not as a “traditional” divinity as had always been the case). This temple was believed to have been built by Trajan’s successor Hadrian (117-138 A.D.) at the northern edge of the complex, in an area that is essentially where Palazzo Valentini stands today. Recent researches carried out in the basement of that building has brought to light ruins of private habitations, some quite substantial, which would appear to exclude the presence of such a temple in that area or at least reduce its possible size.

The Basilica Ulpia as a new tribunal

Trajan’s name was instead linked with another architectural element up to then never present in the Imperial Forums: the Basilica. It was named the Basilica Ulpia after the family name of the emperor, who was of the Gens (or clan) Ulpia. In fact the emperor’s full name was Marcus Ulpius Nerva Traianus. It is very probable that the two apses of the basilica, placed along the short sides, were used for the administration of justice. In this way the presence of courts within semi-circular structures replicated the architectural model inaugurated in the Forum of Augustus.

The Equus Traiani or Trajan’s Horse

The exaltation of the name and the figure of Trajan was also entrusted to the equestrian statue of the emperor (the Equus Traiani, or literally “Trajan’s horse”), placed in the Forum’s square on a base that measured 3,76×7,54 metres, the remains of which were uncovered during the excavations of 1998-2000. The statue is lost, but we know what it looked like thanks to images of it that were reproduced on coins: Trajan was portrayed as a military leader, with a lance with the point facing down (in sign of peace) in his right hand, and in his left, a statue of winged Victory. It is calculated that the statue was 10-12 metres high including the base. Its beauty and the astonishment that it provoked in those who saw it, are attested to by the writings of various authors of the ancient world.

The Commentary of Ammianus Marcellinus

Among these ancient writers was the historian Ammianus Marcellinus (330-400 A.D. circa), who describes in this way the reaction of the Emperor Constantius II (337-361 A.D.), who in 357 A.D. visited Rome: “When he arrived at the Forum of Trajan, a creation unique under the heavens, as we believe, (…) he stopped in amazement, admiring all about him the colossal constructions, impossible to describe nor possible to be imitated by mortal men. And thus putting aside any hope of building something similar, he said that he desired and felt capable of imitating only Trajan’s Horse.” Ammianus also recounts the reaction of the Persian Prince Ormisda, who accompanying the emperor said these words: “But before creating such a horse, my emperor, order that they should build it a stable, to equal this”.

Apollodorus of Damascus

The creator of this extraordinary monumental complex was Apollodorus of Damascus, the celebrated architect that accompanied Trajan in the wars against the Dacians during which he designed a bridge across the Danube at Drobeta, an event that is depicted on Trajan’s Column. His name is linked with other architectural complexes commissioned by the emperor such as the Trajan Baths at Colle Oppio in Rome and Trajan’s port at the mouth of the Tiber River. After Trajan’s death, Apollodorus fell out of favour with his successor Hadrian, who liked to dabble in architecture himself and who, according to legend, had Apollodorus executed because he took offense at the architect having expressed negative judgments concerning the project for the Temple of Venus and Rome, conceived by Hadrian.