The structure in Cologne, Germany, was most likely used to store up to 20,000 scrolls of parchment. (Hi-FlyFoto/Roman-German Museum of Cologne/EPA-EFE/Shutterstock) (HI-FLYFOTO/ROMAN-GERMANIC MUSEUM OF COLOGNE/HANDOUT/EPA-EFE/REX/Shutterstock/Hi-Flyfoto/Roman-Germanic Museum Of Cologne/Handout/Epa-Efe/Rex/Shutterstock)

When the Romans expanded across Europe 2,000 years ago, they made inroads into almost every corner of the continent, fighting as far away as Scotland and sending its coins to what today is Estonia.

But Germany posed a particular challenge. In the year 9 of our modern calendar system, the Romans suffered an embarrassing defeat in the Battle of the Teutoburg Forest near the modern day city of Hanover. They never recovered from it and were permanently pushed back to the western side of the Rhine river, which separates Germany from south to north, 50 miles from Teutoburg. Centuries later, marauders from Germany finally brought an end to the western half of the Roman empire.

Yet the Roman were quite active on the western side of the Rhine and left behind a vast number of architectural masterpieces. Archaeologists still keep discovering remnants of that part of German history. And one of the most astonishing buildings from that era — the country’s oldest-known public library — is only now being uncovered.

Built about 150 years after the Battle of the Teutoburg Forest, its walls recently reemerged after centuries of darkness during the construction of a new community center next to the city of Cologne’s famous cathedral. At first, when the walls were discovered last year, researchers assumed they had come across a community hall dating to the Roman era. But this summer, a more extensive analysis found the building was most likely used to store up to 20,000 scrolls of parchment. (The estimate would put the Cologne library in the same category as the vast Library of Celsus, which was built in Turkey at about the same time.)


A planned glass window will allow visitors to get a glimpse of the long-lost structure in Cologne, Germany. (Hi-FlyFoto/Roman-Germanic Museum of Cologne/EPA-EFE/Shutterstock) (HI-FLYFOTO/ROMAN-GERMANIC MUSEUM OF COLOGNE/HANDOUT/EPA-EFE/REX/Shutterstock/Hi-Flyfoto/Roman-Germanic Museum Of Cologne/Handout/Epa-Efe/Rex/Shutterstock)

The room that researchers believe was used as a library was 65 feet long and 30 feet wide, with a 30-foot-high ceiling, according to estimates. But what really captured the researchers' attention were the roughly 30-inch-deep wall recesses, which bore striking similarities with the setup of other rooms that were used as libraries during the Roman era.

So far, Roman libraries have mostly been found in Egypt or Italy. The Cologne find may be the first such discovery in the Roman Empire’s northwestern regions, which at its peak spanned France, Britain and western Germany.

Across the empire, Roman emperors left their footprint by introducing currencies, occupying territories and constructing buildings that reflected a culture that prospered for centuries — though it was built on the exploitation and oppression of other peoples. While the walls discovered in central Cologne may once have accommodated a library, the use of the word “public” still remains controversial.

In the 1st century A.D. — about 50 to 100 years before the Cologne building was constructed — Roman Emperor Augustus began to embrace state libraries. Originally a Greek concept, the Romans soon started building similarly impressive collections across their territory.

Researchers have since raised doubts over how public those libraries really were, with the University of Georgia’s T. Keith Dix writing in 1994 that anecdotes from that time indicate access remained mostly restricted to “authors close to imperial circles who might naturally be expected to have won access to libraries under imperial control.”

The Roman Empire’s official libraries also appear to have been used “for censorship of literature,” according to Dix.

Which parchments the library’s vast wall recesses accommodated about 2,000 years ago will remain a mystery — parchment and papyrus were notoriously fragile, and many libraries' collections disintegrated from lack of care over the years — but Cologne visitors will soon at least be able to take a closer look at the building’s foundations. The community center’s parking lot that was supposed to be constructed on top of it will now host two fewer parking spaces than planned. Instead, a glass window on the ground will allow visitors to get a glimpse of an era long predating Europe’s current borders.