ROME – An Italian expert in Hebrew manuscripts said Wednesday he has discovered the oldest known complete Torah scroll, a sheepskin document dating from 1155-1225. It was right under his nose, in the University of Bologna library, where it had been mistakenly cataloged a century ago as dating from the 17th century.

The find isn’t the oldest Torah text in the world: the Leningrad and the Aleppo bibles — both of them Hebrew codexes, or books — pre-date the Bologna scroll by more than 200 years. But this is the oldest Torah scroll of the Pentateuch, the five books of Moses, according to Mauro Perani, a professor of Hebrew in the University of Bologna’s cultural heritage department.

Two separate carbon-dating tests — performed by the University of Salento in Italy and the Radiocarbon Dating Laboratory at the University of Illinois, Urbana-Champaign — confirmed the revised dating, according to a statement from the University of Bologna.

Such scrolls are brought out in synagogues on the Sabbath and holidays, and portions are read aloud in public. Few such scrolls have survived since old or damaged Torahs have to be buried or stored in a closed room in a synagogue.

In a telephone interview Wednesday, Perani said he was updating the library’s Hebrew manuscript catalogue when he stumbled upon the scroll in February. He said he immediately recognized the scroll had been wrongly dated by the last cataloguer in 1889, because he recognized that its script and other graphic notations were far older.

Specifically, he said the scroll doesn’t take into account the rabbinical rules that standardized how the Pentateuch should be copied that were established in the late 12th century. The scroll contains many features that would be forbidden under those rules, he said.