The Facist-era reconstruction of the Ara Pacis drew largely on the 1902 work of German scholar Eugen Petersen, who had taken photographs of the various parts of the monument (dispersed among European museums) and created a theoretical photo montage. Fragments found by Italian archaeologist Antonio Pasqui in 1903 and by Giuseppe Moretti in 1937 and 1938 (along with precise measurements made by Moretti’s team) were also included in the final reconstruction, which gave the monument an immediacy and a sense of authenticity.

In the decades since, however, scholars have debated the accuracy of the reconstruction. Given the political passions associated with the rise and fall of fascism, a good deal of this debate has been ideological. But nonpartisans have also raised problems. So is the Ara Pacis Augustae really the Ara Pacis Augustae? The answer is “partly.”

It is now clear that some fragments from the 1903 and 1937–1938 excavations—including footwear, drapery and laureate heads—have not been incorporated into the monument. More damningly, the University of Colorado classics professor Diane Conlin, while studying 16th- and 17th-century drawings of the Ara Pacis in the Vatican (Codex Ursinianus) and in a drawing collection of the 17th-century antiquarian Cassiano dal Pozzo (now housed in the Museo Cartaceo and in Windsor Castle), noticed that a female relief figure identified as Antonia the Younger (holding a child’s hand in the photo) is now incorrectly joined to the back side of a male figure.

These drawings show the original break lines of the panels, which were restored in the 18th century by the sculptor Francesco Carradori. Carradori also carved new heads and other elements for the Ara Pacis relief. (Such restoration—most commonly the replacement of broken arms and legs and sometimes the reworking of weathered surfaces—was common in Europe from the 16th to the 18th century.) In 1902 Petersen suggested that the panels of Antonia the Younger and the male figure be joined. This prompted restorers in the 1930s to conceal the (incorrect) joint with plaster. Luckily, the restorers did not rework the original breaks in the panels, permitting further study of the break lines if the panels are ever disassembled in the future.

Like Carradori and his contemporaries, the ancients were quick to restore worn or damaged monuments. The Ara Pacis’s marble surface appears to have suffered from weathering during its first 300 years, when it was exposed to the elements. (Paradoxically, many archaeological remains are preserved by being destroyed and then covered over with the rubble of ages, protecting them from vandalism or erosion.) Some details on the faces in the processional frieze were probably reworked in the third and fourth centuries A.D.

An important monograph on the Ara Pacis was published in 2003 by Wayne Andersen, formerly of MIT’s Department of Architecture. Anderson’s detailed measurements indicate that although the interior altar can indeed be dated to between 13 and 9 B.C., the monument’s decorated walls date to the time of Augustus’s successor, Tiberius (14–37 A.D.). Tiberius apparently incorporated the Augustan altar within his own shrine to lend gravitas to his troubled reign. Anderson suggests that the loss of the finer distinctions between the earlier and later phases of the monument can be attributed to haphazard reconstruction work undertaken during the Fascist period.

Anderson also suggests, somewhat whimsically, that even if the Fascist restorers had noticed discrepancies, they likely would have kept their mouths shut—as they were under orders to produce a “fully authentic” Augustan monument.