The Treacherous Oath of the Erembalds: A New Look into the Ties of the Group of Count Charles the Good's Murderers

In the year 1127 the reigning count of Flanders, Charles the Good, was murdered by the Erembalds. While the Erembalds have commonly been regarded as a clan in modern historiography, this article refutes this notion and goes beyond biological ties of kinship to examine the social bonds formed through oaths. Oaths played a significant role in the establishment of social ties and, consequently, also in the social organization of the conspiracy behind the murder during the events of 1127. It will be argued that Galbert of Bruges—a notary in the comital administration who composed a detailed source outlining the events following the murder known as De multro, traditione, et occisione glorioso Karoli comitis Flandriarum—linked the conspirators through an oath that was sworn on the eve of the assassination of the count.