“There are two palimpsests here that have Caucasian Albanian text in the erased layer,” says Michael Phelps, the director of the Early Manuscripts Electronic Library and leader of the project. “They are the only two texts that survive in this language ... We were sitting with one of the scholars and he was adding to the language as we were processing the images. In real time he was saying ‘now we have the word for net’ and ‘now the word for fish.’”

Another dead language to be found in the palimpsests is one used by some of the earliest Christian communities in the Middle East. Known as Christian Palestinian Aramaic, it is a strange mix of Syriac and Greek that died out in the 13th century. Some of the earliest versions of the New Testament were written in this language. “This was an entire community of people who had a literature, art, and spirituality,” says Phelps. “Almost all of that has been lost, yet their cultural DNA exists in our culture today. These palimpsest texts are giving them a voice again and letting us learn about how they contributed to who we are today.”

Other palimpsests are written in more common languages like Arabic, Syriac, Latin, and Greek. More than 108 pages of previously unknown Greek poetry were uncovered beneath more recent Arabic and Georgian texts. Three previously unknown Greek medical treatises have also been found, including one that contains the oldest known recipe credited to Hippocrates, the father of Western medicine.

For classical and medieval scholars, the ability to read these lost texts has brought new energy to their field. “This new project has brought a 25 percent increase in the readability [of the Caucasian Albanian palimpsests],” says Jost Gippert, a linguist at Frankfurt University who has been studying Caucasian Albanian for more than a decade.

Phelps and his team are making their findings publicly available online so scholars around the world can study them. It is a timely effort: Recently Saint Catherine’s, which is controlled by the autonomous Church of Sinai, part of the Eastern Orthodox Church, has come under threat from nearby attacks by groups affiliated with the Islamic State. “A big piece of what we are doing is making sure future generations have access to this material despite the geopolitical pressures,” says Todd Grappone, an associate librarian at the University of California, Los Angeles, and another member of the research team.

Some of the palimpsests that the team has recovered, however, suggest the tensions between Islam and Christianity were not always so fraught, and highlight the role the monastery played as a meeting point for the faiths. “We are recovering the history of the monastery from a time when there are almost no historical records,” says Father Justin Sinaites, a Texan who has been the librarian at Saint Catherine’s for the past 10 years and is charged with protecting its parchments. Many of the texts indicate an exchange of ideas and literature between the faiths, with early translations of Christian scriptures and liturgies into Arabic appearing in the palimpsests.

“We are finding evidence of how important texts reached the Arabic-speaking world in the first centuries of Arab rule,” says Sinaites. “I don’t think you can understand the problems in the world today without understanding the history of this part of the world.”

We want to hear what you think about this article. Submit a letter to the editor or write to letters@theatlantic.com.