Source Research

Every historical study is based on sources. It is often more challenging to find relevant sources than it is to identify relevant literature. Many studies rely on original sources which can only be consulted at an archive. Selected archival sources, however, have been published in source editions, while others have been reproduced in digital form (as scans or photographs) for inclusion in archival catalogues or on online databases. Moreover, published texts can be treated as sources, while you can also compile your own sources using the methods of oral history.

For a Presenting Your ResultsProseminarpaper, it is usually a good idea to rely on published sources (or on sources recommended or provided by your lecturer). Working with sources which have to be viewed at an archive is a demanding and time-consuming activity, not least because knowledge of palaeography is often required (i.e. you must be able to read old scripts). Archival research is certainly not necessary (albeit absolutely doable) for a Proseminar paper, for which sources in source editions as well as other more readily accessible sources such as digital copies are usually used. Archival research makes more sense for a Seminar paper or, in particular, for a master’s thesis. Nevertheless, it is still a good idea to familiarise yourself with the demands of archival research from an early stage in your studies by attending one of the History Department’s regular introductory Übungen (tutorial courses) on archival research.

The most important question to consider when searching for sources is what types of sources might be available which are relevant to your topic. It may sound obvious, but you need to be aware, for example, that you will not find any photographs from before the second half of the nineteenth century. Private medieval writings, meanwhile, are highly unlikely to have made the journey into modern public archives. Some knowledge about the political institutions which existed during the time period which you are studying can provide clues as to which records may be available in the archives. Indeed, with some contextual knowledge (and an awareness of which types of sources could be relevant for your research question), it is possible to gauge what types of sources you could find. The different kinds of sources tend to become more varied as the period which you are investigating becomes more recent. Alongside the aforementioned “conventional” sources found in archives and source editions, a diverse range of other types of documents and material objects can also serve as sources, including literature, artwork, films, posters, postcards, etc. These are often held in special collections (at archives or other institutions).

Before you can begin your archival research, you need to make sure that you are at the correct archive. Knowledge about which archives are responsible for which types of collections can help you to assess where the most relevant records for your research may be held. Archival collections are typically indexed in an archival catalogue. Most (larger) archives boast their own online catalogues through which their collections can be searched. Smaller archives often have only a printed and/or card catalogue which must be consulted on site. Different online catalogues offer different search options. An archive plan search (displayed in the form of a fold-out tree diagram) offers a hierarchical overview of all collections held in an archive. Further search options include a full-text search as well as searches by various predefined fields (e.g. by call number or date of creation). The success of any search in an archival catalogue depends on how extensively the archive’s collections have been indexed. Archives usually boast both very well-catalogued collections (sometimes even listing the details of the individual documents within a collection) as well as collections which have been only very roughly catalogued (e.g. by archival container). Many archives possess older handwritten or printed (but not digitised) catalogues which offer a detailed overview of individual collections or collections relating to specific topics. Archival staff can provide you with information about these and other finding aids as well as general guidance on how well-catalogued their collections are. It is always a good idea to approach staff members with any specific questions.

Besides archival catalogues maintained by individual archives, there are also meta-catalogues. These allow you to search through the catalogues of multiple archives in a single search. The most important archival catalogues and meta-catalogues are listed in the section on research resources. In the course of ongoing efforts to digitise their collections, many archives have made their collections available in digital form. These digital copies can often be accessed via an integrated viewer within an online archival catalogue, thus potentially saving you an actual trip to the archives. Normally, however, you will need to order the records which you have found in an archival catalogue on site and/or view them in the archive’s reading room. Most archives allow you to photograph their archival documents.

Since archival sources are often difficult to access (not least because they usually demand a visit to an archive), numerous source edition projects have been established with the aim of making sources more readily accessible to historians.

When is it worth your while to search for a source edition? You are more likely to find one for sources written by well-known authors, for frequently consulted collections, for widely read manuscripts, or for certain types of source (e.g. legal documents). As a general rule, the further back in time which you venture in your research, the more published sources you are likely to find.

Conventional source editions in book form can be found in libraries (and, as such, in library catalogues). Footnotes in relevant secondary literature are usually another good place to find references to source editions. It can also be useful to search through the registers of major source edition projects. For some time now, there has also been an effort to digitise older source editions and to publish new editions directly in digital form. Digital source editions are especially helpful because they allow for the option of a full-text search. Online source databases also give you the option of searching for (printed and digitised) source editions.

Because the digitisation of image sources has proven especially advantageous for researchers – who are thus spared the often onerous task of reproducing printed or original images – there are currently several large projects attempting to make extensive collections of images available via online databases. Many archives with large image collections have also been making an effort to make these collections accessible via their archival catalogues (or other search tools).


Examples of Large Image Databases:

BM Archives. Visual and cartographic material from the Basel Mission Archives, 1550-2000.

Humphrey Winterton Collection of East African Photographs, 1860-1960. Photographs from the colonial period, East Africa.

Institut für Realienkunde des Mittelalters und der frühen Neuzeit (Institute for Realia of the Middle Ages and the Early Modern Age.

Digitaler Portraitindex (Digital Portrait Index).


Bildindex der Kunst und Architektur. Based on the Marburg Picture Index. Access to approximately two million images relating to art and architecture.

Das prometheus-Bildarchiv: High-quality images relating to art, culture and history.