The alliance treaty between Amaury I and al-Adid in Cairo in 1167: Cultural aspects and ideological stakes of an oath in the time of the Crusades.

Abstract

During the second half of the twelfth century, conflicts between the Crusader states and the Zengid dynasty intensified. After the recapture of Edessa in 1151, the Zengids came to dominate most of the Near East and turned their ambitions toward Fatimid Egypt. To prevent the emergence of a power capable of completely encircling the Latin Kingdom of Jerusalem, King Baldwin III, followed by his successor Amalric I, chose to ally themselves with the Fatimid Caliphate.

This article examines the ceremony between the Latin king Amalric I of Jerusalem, represented by Hugh of Caesarea, and the Fatimid caliph al-ʿAdid in Cairo in 1167. As part of the conclusion of a pact of assistance, the caliph has to swear an oath to the envoy of the king of Jerusalem. For this oath to be recognized as valid by the crusaders, it had to conform to a strict protocol, both in the words spoken and in the gestures performed. However, this ritual conflicted with certain practices specific to the Fatimid tradition. Several aspects of this ceremony need a particular attention: what cultural differences can be identified in this encounter ? What do they imply for the course of the negotiations ? How was this event perceived by the Fatimid dignitaries ? And how sincere was the caliph, who swore an oath in a language he did not understand ?

The principal source used in this study is the account given by William of Tyre in his Historia rerum in partibus transmarinis gestarum. He describes the ceremony in detail and sheds light on the way each side perceived and interpreted the attitudes and words of the other. This testimony—the only surviving account of the ceremony—highlights the subtlety of diplomatic exchanges, the implicit tensions underlying official encounters, and the manner in which ceremonial functioned as a genuine diplomatic language. Recent studies, notably that of Michael Köhler in 2013, have discussed this alliance, focusing primarily on its diplomatic and political dimensions.

This study concludes that, in the context of the second half of the twelfth century, marked both by the weakening of the crusader states and by that of the Fatimid Caliphate, the obligation imposed upon the caliph to conform to foreign customs may have been perceived by Fatimid dignitaries as a form of humiliation. The analysis of this episode thus reveals the complexity of power relations, strategies of influence, and the ways in which words, gestures, and ceremonial staging became both instruments of negotiation and potential sources of misunderstanding.

Key words: Oath; Diplomacy; Ceremonial; Crusade.