If Roman religion has been constructed as something of a void, defined in opposition to the Christianity that succeeded it, and the religions of the Greeks that preceded it, an important part of how it has been shaped is through comparison to forms of religious practice that have been called the ‘mystery’ or ‘Oriental’ cults.1 For some, in harking back to the kinds of ecstatic religious experience of the Greek world framed, for example, by Euripides’ Bacchae, these cults evoke the Dionysian dynamism of a Nietzschean archaic;2 for others, in their creative invention during the imperial period, their momentum owing to adherents rather than the state hierarchy, their possible soteriology and their vibrant material culture, they have seemed the ancestors of Christianity.3 Mystery cults are only a subsection of religion in the Roman period, but they have been seen as forming a distinct and peculiar category of their own.4