For the first time in 100 years, Italian archaeologists have discovered a rare cippus, or boundary stone, used to delineate the borders of ancient Rome. As the Associated Press (AP) reports, the limestone slab—one of only 11 known to survive today—dates to 49 C.E., when the Roman emperor Claudius redrew the city’s outer limits.
Researchers found the stone in June while conducting excavations ahead of construction of a sewage system beneath the Mausoleum of Augustus, notes a statement. The engraved rock was one of around 140 installed by Claudius to mark Rome’s pomerium, a sacred space where construction, farming and fighting were banned.
According to the Vatican Museums, which house a different cippus dating to Claudius’ reign, the boundary separated Rome from its surrounding territories, dividing the land into the city proper and the broader Ager Romanus.
Legend holds that Romulus, the mythological founder of Rome, created the city’s first pomerium by plowing a furrow in the eighth century B.C.E. Romulus supposedly killed his twin brother, Remus, after Remus jumped over the perimeter in jest.
“The founding act of the city of Rome starts from the realization of this ‘pomerium,’” Claudio Parisi Presicce, director of the Archaeological Museums of Rome, told reporters at a July press conference, as quoted by the AP.
Over time, Rome’s borders shifted beyond its original pomerium. Claudius, who ruled from 41 to 54 C.E., undertook a significant extension of the city limits, reworking the boundaries to incorporate the Aventine Hill, one of Rome’s famed seven hills. Per Tom Metcalfe of Live Science, the new border also covered the Campus Martius, or Field of Mars, which boasted a rich array of public buildings, including the Mausoleum of Augustus.
“[Claudius’] goal was not to increase the civic space of Rome, so much as to celebrate his expansion of the Roman Empire itself,” Lisa Marie Mignone, a classical studies scholar at New York University who was not involved in the recent dig, tells the Daily Beast’s Candida Moss. “[It was] a sacral, topographical and physical way to showcase [in] Rome his renewed expansion of the boundaries of the Roman Empire.”
In recognition of his military accomplishments (most significantly, the conquest of Britain in 43 C.E.), the emperor had each boundary stone inscribed with the same message: Claudius “extended and redefined the pomerium because he had increased the boundaries of the Roman people.”
At the July press conference, Parisi Presicce, as quoted by Wanted in Rome, lauded the newly discovered stone as “an extra piece of the jigsaw for the understanding of ancient Roman society.”
Found in situ—meaning the original location where it was installed some 2,000 years ago—the travertine slab has since been moved to the Ara Pacis Museum, where it is on view alongside a replica statue of Claudius. The stone will eventually be displayed at the Mausoleum of Augustus, which reopened to the public earlier this year after a lengthy restoration.
“Rome never ceases to amaze and always shows off its new treasures,” says the city’s mayor, Virginia Raggi, in the statement. “This is an exceptional find: Over the course of time, only ten other [boundary stones dating] to the time of Claudius have been found, and the most recent, to date, was found in 1909.”