This article discusses fabrications and alternative histories, and their relationship with antiquarian and early archaeological practice, in the Baroque world through the case of an alabaster urn reportedly found in the garden of a Swedish royal castle in 1685. The urn, decorated with a strange inscription, is used to address broader issues of how the past was conceived in the Baroque world, and how the relationship between the past and present was manipulated through antiquarian research. Certain characteristics of the urn and its cultural life have led modern scholarship to dismiss the artefact as 'unauthentic' and hence uninteresting, whereas this article seeks to reconsider the nature and meanings of fabricating the past in the 17th century. It will be argued that the past was not fixed in the Baroque world, but various material and magical practices enabled altering the past. It is against that background, and within the Baroque relational understanding of reality, that the 17th-century interest in and manipulations of the urn must be understood.