Much has been written about the close connection between the opening of archives and the new historical production since 1800. Modern European historiography was and still is based largely on the documents conserved in them. The state has played a crucial role in the field of archives also by educating and appointing specialized staff to order the document series and render them consultable through inventories, and finally by slowly and cautiously opening the archives to scholars and the general ‘public’
. The maps of 1830, 1850 and 1878 show the very slow opening of the archives to their new professional clientele. They represent only those state archives that actually admitted historians, had reading rooms for them and were prepared to issue the documents requested from them.
The maps clearly show that the administrative organization of archives has always depended heavily on the constitutional order of the state. Federal states like Switzerland and Germany, or ones with long traditions of administrative autonomy of their historical regions like the Netherlands or Spain, have preserved a decentralized structure. But the majority of states did follow the pattern of centralizing their state archives and organizing them by starting at the center – often the capital city – and then slowly extending the process to the periphery or provinces, thus following the pattern of the French administration. During the twentieth century, the European maps of archives clearly evidence the heavy effects of state bureaucratization. Everywhere, administrative routines since the nineteenth century had produced kilometers and tons of archival documents. The landscape of archives slowly changed in the last decades of the twentieth century under the impact of the collection of every kind of document to do with contemporary history. State papers increasingly became just one variety of sources together with photographs, film reels, radio recordings, and oral testimonies in media of various kinds. Other historical agents like enterprises, associations and universities have their own archives or consign their documents to specialized archives administered by private organizations or public foundations. Our maps can only to some extent mirror the new pluralism.
Collected are archives on the state or national level or that are part of a national archival system (federal or regional level included). National archives on special topics, such as film or media archives, as well as party archives (when of greater relevance to national history), are also represented in the data.
Archives are not displayed on maps until they are accessible to historians and the public. Therefore their appearance on maps does not match their founding date.