Historical Archive of the City of Cologne up at the site of the collapse (a large hole in the ground), where around 95% of all archival items could be held until August 2011, albeit scattered and in many cases badly damaged. Archive repositories all over Germany offered space to store the damaged and only roughly cleaned documents: wet materials were flash-frozen to prevent mold growth. "Itinerant archivists" worked in the receiving archives all over the country and began the task of re-identifying and re-cataloging. A newly installed centre for restoration and digitization on the outskirts of Cologne started working in 2011, with a total cost for restoring
History of the Jews in Cologne and established in the 1st century AD, as the Roman "Colonia Claudia Ara Agrippinensium" in Ubii territory. It was the capital of the Roman province of "Germania Inferior" and the headquarters of the military in the region. Cologne was an important city in Roman times. H. Nissen assumes a much greater population for Roman Cologne than it was in the Middle Ages, when he estimates it was between 30,000–40,000. It is reasonable to assume that the spread of Christianity in any Roman province was preceded and accompanied by the existence there of Jews. The presence of Christians in Cologne in