In 79 CE, Mount Vesuvius erupted in what would become one of humanity’s most infamous ancient tragedies. Tens of centuries later, archaeologists eagerly dug through the ash and pumice to rediscover the buried Roman cities of Pompeii and Herculaneum in all their preserved glory. In their eagerness, however, they may have missed an important layer of history.

While working in the Insula meridionalis—the southern quarter of Pompeii’s ancient urban center—archaeologists uncovered evidence confirming the hypothesis that, after 79 CE, people returned to live among Pompeii’s ruins for hundreds of years. The team’s findings, which they describe in a study published this week in Pompeii’s excavation’s E-Journal, shed light on events that have long lived in the shadow of better-studied history.

“The epochal episode of the destruction of the city in 79 AD has monopolized memory,” Gabriel Zuchtriegel, director general of Pompeii’s archaeological park and co-author of the study, said in a park statement. “In the enthusiasm of reaching the levels of ‘79, with wonderfully preserved frescoes and still-intact furnishings, the faint traces of the site’s reoccupation were literally removed and often swept away without any documentation.”

Not all survivors of that terrible day would have had the means to start over somewhere else. According to the researchers, this could explain why some may have returned to the destroyed city, whose upper levels were still visible above the ashes. Soon enough, vegetation would have also grown back. The returning former residents may have also been joined by other people “with nothing to lose,” according to the statement. After all, there were riches to be found among the ashes and victims’ bodies.

As such, life returned to Pompeii. People lived among the ruins of the buildings’ upper floors, using the former ground floors as cellars and caves to set up fireplaces, ovens, and mills. Archaeological evidence suggests that the new community was likely a precarious settlement without the usual ancient Roman infrastructure and services. Nonetheless, the settlement lasted until the 5th century CE. Another devastating volcanic eruption may have played a role in the city’s final abandonment.

“Thanks to the new excavations, the picture is now clearer: post-79 Pompeii re-emerges,” Zuchtriegel explains. “Instead of a city, [it’s] a precarious and grey agglomeration, a kind of camp, a favela among the still-recognizable ruins of the Pompeii of old.”

Emperor Tito had actually tasked two ex-consuls with promoting the re-founding of Pompeii and Herculaneum. Needless to say, the mission was a failure.

“In these cases, we archaeologists feel like psychologists of memory buried in the earth: we bring out the parts removed from history,” concluded Zuchtriegel. “This phenomenon should lead us to a broader reflection on the archaeological unconscious, on everything that is removed or obliterated or remains hidden, in the shadow of other apparently more important things.”