This article, first presented as part of a conference entitled What is private international law? , responds to this question through analysis of four different identities through which private international law has been viewed. It begins by exploring two contrasting classical approaches, under which private international law is concerned with the international ordering of state power, or with the national recognition of private rights. It then turns to examine the US and EU private international law revolutions, and the very different further identities of private international law which have emerged as a consequence of each. After reflecting critically on the experiences of these revolutions, the article offers some concluding thoughts as to how the identity or identities of private international law can or should be constructed, arguing that there are valuable lessons and potentially propitious elements in each of the four examined identities