What has by now become the master narrative of the history of sexuality holds that not only homosexuality but the whole concept of sexuality is a creation of nineteenth-century bourgeois society. This article argues that sexual identities, constructed through what Eve Kosofsky Sedgwick calls "minoritizing discourses," can be found much earlier, in premodern Western societies. In the European Middle Ages, for example, although there is nothing congruent to a modern homosexual identity, prostitution was a sexual identity in any relevant sense of the word. This case raises the question of whether the interplay between act and identity might not be more complex than many interpreters of Michel Foucault would make it, and whether the fact that sexuality is socially constructed means that it was constructed only in the nineteenth century.