Eni's historical archive has a well-articulated structure, the result of a long process of care and work by many people. Set up in the 1980s by Enrico Mattei's assistant, Vincenzo Gandolfi, to store the chairman's letters, the historical archive office only took form almost 20 years later, when the Superintendent for Archives of Lazio expressed "great historical interest" in it. Multifaceted by its very nature, given its subject matter, the archive began to be gathered in 2006. Locating and bringing together the sources from their various offices and sites took years, what with physically moving, ordering and describing all the material. It involved a lot of projects, people and descriptions, first on paper then in digital form. The same wide range of work was done on the archive's structure, which also had to be moved about (around 40% of the material is still being filed, on top of the partial corrections that will need to be made on later arrivals). The most prestigious series, the first to be sent off for digitisation, were already in the process of being standardised and therefore met the requirements. As we went ahead with sending off the material, however, we realised that the complexity of the archive was making the software tools for automatic extraction harder and harder to use.