When I returned to Rome from Spain and Gaul after successfully completing campaigns in these provinces, the Senate consecrated the Ara Pacis Augustae (Altar of Augustan Peace) at the Campus Martius in honour of my return; it was to be a place where magistrates, priests, and vestal virgins would hold annual sacrifices.
This is from Emperor Augustus's accounts of his campaigns in Gaul and Spain. And in fact it was he who in 13 B.C. called the vote for the altar's construction and in 9 B.C. dedicated the Ara Pacis Augustae to peace, personified as a Roman goddess.
The altar was built on the exact spot in Campus Martius where victories were traditionally celebrated. Its only purpose was to aggrandize Augustus's campaigns and to glorify the Pax Romana: the period of increased prosperity resulting from his reign.
Moreover, Augustus was Caesar's adopted son, and to legitimize his seizure of power, it was crucial to emphasize his connection with his illustrious ancestor, Aeneas.
The ceremony inaugurating the Ara Pacis took place on the birthday of Augustus's wife, Livia.
It was an impressive structure, but like most of Rome's monuments, it became buried over time beneath the constantly rising ground level. It wasn't until the end of 1568 that the first fragments were uncovered. During the 1800s a series of excavations followed one after the other in quick succession; following work in 1938, the monument was finally restored in its entirety (albeit with some inaccuracies). A pavilion, built expressly for this recovery work, was situated alongside the Mausoleum of Augustus, the funerary monument built by the emperor. However, the original location of the Ara Pacis was probably a considerable distance away.Its original appearance was reconstructed based on descriptions found in written sources as well as depictions found on Roman coins. It was a nearly square enclosure mounted atop a low podium, with the altar inside, up a flight of stairs.
The enclosure was covered inside and out with skilfully executed decorative reliefs; figures of different thicknesses made it possible to perceive the various depths of the scene.
The Ara Pacis successfully blends many different styles: classical Greek style in the procession friezes, Hellenistic style in the panels, and the typically Roman style of the altar decoration. This variety and eclecticism suggest that the work was probably carried out by Greek workshops.
The exterior frieze has floral and small animal motifs. On the side with the altar entrance are the Lupercal Panel and Aeneas Sacrificing to the Penates. The first panel, of which only a few fragments remain, illustrates the myth of the founding of Rome: recognizable are the god Mars and the twins Romulus and Remus being nursed by a wolf. The second scene depicts Aeneas, with covered head and accompanied by his son Ascanius, offering a sacrifice at an altar to the Penates, the household gods that protect the family. The relief on the other side, which depicts the Personification of Rome seated atop a pile of weapons, is however almost completely lost.
The short sides depict a procession consecrating the altar, resembling the frieze found at the Parthenon in Athens. There are two parts: one with the priests and the other with Augustus's family. The family is carefully arranged, based on succession to the throne, and it is no coincidence that the figures are located on two floors. Augustus is surrounded by his retinue and is wearing the robe of Pontifex Maximus (the highest authority). Like Aeneas, his head is covered. The imperial family is bit further in front: discernable are Augustus's lieutenant, Agrippa, then the emperor's nephew and wife, and followed by siblings, half-sisters, and other potential successors to the throne.
The north side is in much worse condition, and the heads of the figures were reconstructed during the 16th century.
The inside face of the enclosure has vertical grooves mimicking a fence, probably the same one that was originally used to enclose the sacred area. Most ancient Roman altars were surrounded by a sacred enclosure.
The altar was accessed via a series of steps and was used for animal sacrifices. It is decorated with female figures that may represent the provinces of the Empire. The uppermost frieze, however, depicts the annual sacrifice held there with the Vestal Virgins and the Pontifex Maximus, together with priests and the animals to be sacrificed.
In contrast to those on the exterior of the enclosure, the figures carved on the altar are depicted in high relief.
In 2006 the old pavilion housing the ancient monument was replaced by a modern building designed by the architect Richard Meier. The stainless steel and travertine structure has sparked varied reactions and heated debate.