In 1889, an Italian librarian's faulty identification sentenced to archival obscurity an antique Torah scroll that has turned out to be the oldest complete such scroll in existence.

This week, University of Bologna Professor Mauro Perani announced the results of carbon-14 tests authenticating the scroll's age as roughly 800 years old.

The scroll dates to between 1155 and 1225, making it the oldest complete Torah scroll on record.

Like all Torah scrolls, this one contains the full text of the five Books of Moses in Hebrew and is prepared according to strict standards for use during religious services.

What a 19th-century cataloguer had interpreted as clumsy mistakes by what he guessed was an awkward 17th-century scribe provided the very clues that led Perani to investigate further. National Geographic spoke by telephone to Perani about his rediscovery.

What led you to take a second look at the scroll?

In 2012, a colleague and I decided to write a new catalog of the [University of Bologna] library's Hebrew manuscript collection. The original librarian and cataloguer from 1889, Leonello Modona, was an educated man but not a scholar. He had dated this scroll to the 17th century with a question mark.

He described the writing in this scroll as "an Italian script, rather clumsy-looking, in which certain letters, as well as the usual crowns and strokes, show uncommon and strange appendices." But when I went to examine the scroll, I saw immediately that it was not the "bad" writing that Modona described. These Hebrew letters were in the Oriental style, not of Palestine, but of the Babylonian tradition, and from a much earlier time than the 17th century.

So what did you do?

I consulted with other colleagues and experts who agreed that this scroll originated from some time between the end of the 11th and the beginning of the 14th century. I then pursued carbon-14 testing at the University of Sorrento; the results showed a date of between [the] second half of the 12th century to [the] beginning of the 13th century. In addition, a second carbon-14 test at the University of Illinois at Urbana-Champaign confirmed the first result.

Even before you received the authentication of the carbon-14 dating, were there clues that led you to focus on an early date?

At the end of the 12th century Maimonides [a famous rabbinic authority] set down the rules for how to copy Torah scrolls, and those fixed rules have been followed ever since. This scroll's copyist did not know of those rules. Those rules would have forbidden him from using some of the graphical elements found here, such as use of compression of letters, line justification, and which letters can have [decorative] "crowns" on top.

There is more freedom here. There are also passages whose graphical layout is identical to that of the Aleppo Codex [a Bible in book form], which dates to the 10th century. This all means that either the Torah scroll was made before the death of Maimonides, who died in 1204, or the copyist had not yet learned of those rules. Remember, there was no Internet then to spread the news immediately.

So when did the University of Bologna first obtain this Torah scroll—and how?

This scroll has been at the University of Bologna library for centuries. It's very possible that at some time it came into the possession of a monastery, was later taken to Paris after Napoleon suppressed the monastic and religious orders, and finally restored to Bologna after Napoleon's collapse.

How significant is this discovery?

This is important because this is the entire Torah scroll, the most ancient entire scroll that we know of. We have fragments of other Torah scrolls from the Cairo Geniza that date to the same time or earlier, and they show identical styles to this copyist. Maybe we will find another Torah scroll that is older, but for now this is it.