[1][2] The archive contains official records and private documents from all ages of Cologne history, as well as an extensive library of manuscripts.

[4] The work of communal archives in the state of North Rhine-Westphalia is based on the Archivgesetz des Landes NRW bill of 1989.

An early programme of holding archival records in Cologne was the so-called shrine system (Schreinswesen), used for documenting citizens' rights.

A shrine (Schrein, from Latin: scrinium) was a wooden chest or cabinet where parish administrations stored records and charters.

Such shrines were used for records storage throughout the Middle Ages and into early modern times, most notably in the parish of St. Lawrence near the Cologne town hall.

[6] In medieval Cologne, valuable goods and important trade documents were frequently stored in vaulted warehouses that were specially built in backyards.

As the city and its national and international trade thrived and prospered, the municipal administration began to plan further storage to house the growing number of documents in an adequate space.

The Kölner Verbundbrief charter, a municipal constitution document of 1396, was granted pride of place in a chest decorated with a crown.

The Ratsbibliothek was one of the few Cologne libraries that did not suffer major losses during the French occupation in the early years of the 19th century.

In 1818, the city of Cologne was bequeathed Ferdinand Franz Wallraf's major collection of art, books, and manuscripts.

Among other material, he acquired documents from the estate of Hermann von Weinsberg, a 16th-century Cologne jurist famous for his autobiographical writings.

A new purpose-built structure to house the municipal archive and library was erected between 1894 and 1897 to a Gothic revival design by Friedrich Carl Heimann; it was inaugurated in December 1897.

[12] The new building was large enough to accommodate the archive at a time of accelerated growth when the city of Cologne was absorbing many previously independent towns and villages.

However, since all records and manuscripts had been moved into secure storage as early as September 1939, the archive did not suffer any substantial loss.

In 1971, a six-story archive building by architect Fritz Haferkamp was built at Severinstraße in the southern part of Cologne's city centre.

In a move away from the contemporary popularity of electromechanical air conditioning, Haferkamp preferred a structural-physical, self-regulating solution that needed only little additional climate technology.

[13] For maximum protection of the stack rooms against atmospheric exposure, an armored concrete frame was encased by a brick wall with a thickness of 49 centimetres (19 in).

Public prosecutors in 2017 confirmed that the construction of a new underground railway line of the Cologne Stadtbahn system had been the cause.

[3] The main holdings of the archive were stored in the stacks building, including the medieval manuscripts of the Wallraf collection.

Other holdings, mainly those stored in the ground floor extension with the reading room, such as the film and photograph collection and about 40,000 charters were evacuated.

[citation needed] The years after the collapse were characterized by three main tasks: the recovery and emergency conservation of the scattered archival documents; their step-by-step cleaning, restoration, and digitization; and the investigation of the cause for the disaster through a legal process.

A disaster recovery building (Bergungsbauwerk) was set 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.

[24] In 2013, in the context of the city's financial crisis, local political debate began to move towards re-considering this decision, and even to imposing a planning moratorium.

[28] Before the 2009 collapse, the archival holdings included: Among the 700 private deposits are those of writer and Nobel laureate Heinrich Böll,[29] and writers Jakob Ignaz Hittorff, Irmgard Keun, and Hans Mayer, architects Ernst Friedrich Zwirner and Sulpiz Boisserée, collector Ferdinand Franz Wallraf, composers Jacques Offenbach and Max Bruch, conductor Günter Wand, and philosopher Vilém Flusser.

The Barbarastollen holds around 638 microfilms with one million images in varying grades of quality from the various Cologne collections, including the municipal archive.