Ara Pacis Augustae (13-9 BC): Augustus's Altar of Peace

The Ara Pacis Augustae, the “Altar of Augustan Peace”, is a marble altar in Rome that the Senate voted on 4 July 13 BC to celebrate the emperor Augustus’s safe return from Spain and Gaul. Dedicated on 30 January 9 BC, it honoured Pax, the goddess of peace, and its sculpted walls are among the finest surviving works of Roman art. Rediscovered in fragments and reassembled in 1938, it now stands in a modern museum beside the Tiber.

Background: a monument to peace

By 13 BC Augustus had ruled Rome for more than a decade as princeps, “first citizen”. After three years in the western provinces he returned to Rome, and the Senate decided to mark the occasion. Augustus records in his own account of his reign, the Res Gestae, that the Senate decreed an altar of Augustan Peace to be consecrated near the Campus Martius, where magistrates, priests and Vestal Virgins would offer an annual sacrifice.

The altar expressed a central idea of the new regime: that Augustus had ended the civil wars and brought peace and plenty. That message underpinned the long Pax Romana. The dedication date, 30 January, was the birthday of his wife Livia.

Design and reliefs

The altar stood on the Campus Martius, beside the Via Flaminia, the great road leading north out of Rome. A rectangular marble enclosure, roughly 11.6 by 10.6 metres, surrounds the altar itself, which is reached by a flight of steps. The enclosure walls are carved inside and out.

On the outside, the lower half of each wall is covered with flowing acanthus scrolls, full of small animals and birds, symbolising abundance. The upper half of the two long sides shows a procession. It includes Augustus, priests, lictors (attendants), and members of the imperial family, among them, in most identifications, Agrippa, Livia, Tiberius and children of the household. The procession probably refers to the ceremony of 13 BC, but scholars still debate who each figure is.

The short ends carry four panels. One shows a figure sacrificing a sow, usually identified as Aeneas, Rome’s legendary Trojan ancestor, though some scholars propose Numa, the second king. Another, badly damaged, showed the she-wolf with Romulus and Remus. On the east side, a seated goddess with two infants and fruitful nature around her is variously identified as Tellus (Earth), Italia or Pax. A fourth panel, now fragmentary, showed the goddess Roma.

Rediscovery and reconstruction

Over the centuries the altar was buried by rising ground levels, and its site ended up beneath a palace on the modern Via del Corso. In 1568 carved fragments were found during building work, and pieces ended up in collections in Rome, Florence and Paris, including the Villa Medici, the Uffizi and the Louvre.

In 1879 the German archaeologist Friedrich von Duhn recognised that scattered reliefs belonged to the Ara Pacis. Excavations began in 1903 but were halted by groundwater. In 1937-38 engineers working under the archaeologist Giuseppe Moretti froze the waterlogged soil so the remaining pieces could be extracted safely beneath the building.

Mussolini’s regime wanted the altar ready for the 2,000th anniversary of Augustus’s birth in 1938. The altar was reassembled, with plaster casts filling gaps and copies of pieces held abroad, in a new pavilion beside the Mausoleum of Augustus, about 200 metres from its original site. It was inaugurated on 23 September 1938. The text of the Res Gestae was carved on the wall of the new square.

The modern museum

The 1938 pavilion by Vittorio Ballio Morpurgo deteriorated, and in the 1990s the city of Rome commissioned the American architect Richard Meier to design a replacement. His glass and travertine building opened in 2006. It was the first major new building in Rome’s historic centre since the fascist era and drew fierce criticism from some for its modern style, while others praised it for showing the altar in natural light.

Research has also shown that the altar was originally painted. Traces of pigment suggest bright colours, and the museum has used light projections to show how it may once have looked.

Timeline

• 13 BC, 4 July: The Senate votes the altar on Augustus’s return from Spain and Gaul.
• 9 BC, 30 January: The Ara Pacis is dedicated.
• 1568: Carved fragments are found under a palace on the Via del Corso.
• 1879: Friedrich von Duhn identifies the fragments as the Ara Pacis.
• 1903: First excavation attempt is halted by groundwater.
• 1937-38: The site is excavated by freezing the ground; the altar is rebuilt near the Mausoleum.
• 1938, 23 September: The reconstructed altar is inaugurated.
• 2006: Richard Meier’s Ara Pacis Museum opens.

Why it matters

The Ara Pacis is the clearest surviving statement in stone of how Augustus wished his rule to be seen: pious, peaceful, rooted in Rome’s legends and centred on his family. Its reliefs influenced later Roman state art, and its modern history shows how ancient monuments can be reused for political purposes in the present.