The Investiture Controversy (or Conflict, Struggle, Contest, Streit, Querelle, Lotta, etc.) is a term used to describe the disputes that broke out between popes and European rulers during the late eleventh and early twelfth centuries, the most consequential of which erupted in 1076 between Pope Gregory VII (1073–1085) and the German king, Henry IV (1056–1106). It continued under their successors until the compromise settlement of 1122. The term reflects a simplification of the conflict into the issue that became paramount only in its last phase – whether kings or other lay lords had the right to appoint bishops and invest them with the symbols of their office. But the issues at stake were larger than this single one, and included matters involving the general reform of the church, clerical celibacy, simony, schism, excommunication, deposition, the validity of ordinations and sacraments, legitimate violence, and others. Often styled at the time as the discord between kingship and priesthood (inter regnum et sacerdotium), the episode has gone down in history as one of the great showdowns between "church" and "state," or spiritual and secular power, in European history.

The conflict was both ideological and martial. Regarding the former, a large number of polemical writings were produced that advocated and articulated specific positions. Presented here is a list of over 200 primary sources relevant to the Investiture Controversy. Many of these works have held the scholarly interests of medieval historians for over a century; others are less well known. The aim with this data set is to present a thorough list of sources in rough chronological order to facilitate further inquiry and research. A timeline of key events from the late eleventh and early twelfth centuries is also provided to show how events on the ground like councils, battles, deaths of prominent individuals, and the like may have prompted specific writings. At the core of the source list are the polemical works written in the heat of the events, but it also comprises chronicles, biographies, poetry, and other source types. Some sources can be dated with great precision, while others can only be narrowed down to a range of years. Due to this uncertainty, it should be noted that just because one source follows another in the list, that does not necessarily mean that it was composed later.

The source list consists of date ranges, authors, and titles in the headings, and a click will expand the panel to display further essential details, such as modern editions and surviving manuscripts. Links to modern editions are made possible either through their availability in the major source collection for German history, the Monumenta Germaniae Historica (most of which is available freely online), or editions available elsewhere online at places like the Internet Archive. Recent digitization projects at many European repositories have meant that links are also provided for many manuscripts.

The inclusion of lists of surviving manuscripts can provide some sense of a work's geographical and chronological diffusion, but caution must be exercised when considering this metric. Some works known to have played a central role in the debates exhibit a poor diffusion among surviving manuscripts. It has been noted that the survival of many important letters – the preferred polemical format of the time – depended on their incorporation into letter collections in the twelfth century, the purposes of which, in some cases, seem more stylistic and rhetorical than ideological. A list of the most important letter collections containing sources for the Investiture Controversy can be found here.

This brief introduction is meant merely as an introduction to the source list, and not as an introduction to the Investiture Controversy itself. The scholarship on this issue, in all European languages, is immense. In English, a good place to start can be found in nearly anything by I. S. Robinson (link).


Basic abbreviations employed in the data set to facilitate navigation include:

BHL = Bibliotheca hagiographica latina (numbering system for hagiographical texts) (link)
JL = Jaffé-Löwenfeld (numbering system for papal letters) (link)
MGH = Monumenta Germaniae Historica (for series abbreviations see dmgh)


Some major manuscript repositories are also abbreviated:

BAV = Biblioteca Apostolica Vaticana – Vatican City
BnF = Bibliothèque nationale de France – Paris, France
BSB = Bayerische Staatsbibliothek – Munich, Germany
GWLB = Gottfried Wilhelm Leibniz Bibliothek / Niedersächsische Landesbibliothek – Hannover, Germany
HAB = Herzog August Bibliothek – Wolfenbüttel, Germany
KBR = Koninklijke Bibliotheek van België / Bibliothèque royale de Belgique – Brussels, Belgium
ÖNB = Österreichische Nationalbibliothek – Vienna, Austria
WLB = Württembergische Landesbibliothek – Stuttgart, Germany



This source list is a work in progress.

Any comments, feedback, corrections, etc. are welcome via email: jrwebb [at] bridgew [dot] edu.