Just a short walk from the Pantheon, in Piazza di Pietra, are the majestic remains of the Temple of the deified Hadrian (Hadrianeum), built by Antoninus Pius, Hadrian’s adopted son and successor. Only eleven columns with capitals and the cella wall of the original temple are still visible today.
In 1696, during the pontificate of Pope Innocent XII, the surviving part of the temple was incorporated into a large building designed by Carlo Fontana to house the central Customs Office. In 1879-82 the building was modified, and its Baroque decoration was replaced by a simpler one; in 1928, the cella wall was freed from later additions. Today the building houses the Borsa Valori di Roma, Rome’s stock exchange.
The temple to the divine Hadrian was erected in the Campus Martius (Field of Mars) and was dedicated in AD 145. The order is Corinthian, and the columns are 15-metre-high and made of Proconnesian marble with its characteristic greyish colour. Only the lower part of the entablature is left from the original (the highest section being a reconstruction). 16th and 17th-century drawings showed the edifice’s appearance when the original entablature was still in place.
The cella and columns (part of the north side of the temple) stand upon a stylobate and large podium. A deep excavation in front of the colonnade has exposed the original ground level of the temple precinct, 5 meters below the present floor level.
Several excavations between the sixteenth and twentieth centuries in the vicinity of the temple have identified the line of a monumental wall in peperino tufa running parallel with the northern flank of the temple. This wall was part of a large enclosure wall that formed the temple’s porticus. During these excavations, a series of marble reliefs were also discovered. A recent theory suggesting that they adorned the attic of the portico has been favoured by scholars. However, various other theories have been offered; the attic of the temple, the temple podium or the outer temple portico.
Nineteen panels survive from what was potentially a much larger series. They were carved in relief with personifications of provinces altered with depictions of captured arms and armour. The reliefs were found without inscriptions, but each figure wore and carried distinctive costumes and attributes. Scholars have attempted to name the provinces they were meant to represent, but unfortunately, they have not all been successfully identified.
The panels are on display in five different collections in Rome and Naples. Seven provinces and three reliefs with trophies are prominently displayed in the courtyard of the Palazzo dei Conservatori in Rome (Capitoline Museums).
Two restored panels with the personification of provinces are housed in the Palazzo Massimo alle Terme.
Three other reliefs with the personification of provinces and two with trophies are housed in the Naples Archaeological Museum.
The other known elements are scattered in several Roman collections or lost but are known from drawings from the Renaissance and later periods.
The choice to represent the personifications of Provinces within a temple dedicated to the divine Hadrian had a very specific propaganda meaning; these “Provinciae Fideles” were the symbol of political order and a pacified empire, the clearest beneficiaries of Hadrian’s foreign policy of pacification and unification.