Security History is a new field in historical research. Conspiracies and Conspiracy Theories have attracted since some years great attention, both in historical and in social research. A thorough study of those both opposed and mirroring key phenomena and concepts does not exist. This contribution tries to outline a sketch of the development of their interwoven history, how (imagined) conspiracies challenged new means of security production and vice versa. The main assumption is that a) a translocal public sphere, b) concepts, practices and means of institutionalized security production, and c) developed narratives that contain conspiracy theories only emerge together from the Renaissance onwards. Only if there is a public sphere in which conspiracy theories can circulate anonymously they become themselves an element of historical agency. Security as a leading principle of politics emerges only with the development of the state. The contribution outlines the steps of change from confessional age to Enlightenment, to the Revolutionary age and to Modernity, identifying mainly two important systematic changings which affect the security/conspiracy combination (Emergence of observability alongside the politics/religion and Ancien Régime/Bourgeois Society distinctions). It finally asks if there is currently happening a third epochal shift of comparable importance.