Hana Komárková, in her contribution “Gospel or the Immaculate Mother of God? Transformations of Oaths in Opava in the 16th and 17th Centuries”, focuses on the phenomenon of the oath. The variability of confessional and political conditions in Opava during the 16th and 17th centuries was also reflected in the transformation of ceremonies legitimizing social order and ruling authority. Oaths, as part of these acts using traditional means of symbolic communication, served as a specific communicative tool of performative nature, guaranteeing the credibility of declarations through the invocation of transcendent authority. The way this functioned is analyzed through examples from the records of council renewal in the Opava Ratesspiegel from the second half of the 16th century and the text of the oath of allegiance sworn by the citizens of Opava to the Princes of Liechtenstein in the first half of the 17th century.