This chapter deals with the role of corporations in private law. Private law relations have never been built on bilateral contracts alone. Collective actors in the form of corporations have always played an equally important role. To this extent, private law relations mirror the distinction between markets and organizations that is commonplace in economic theory (see Chapters 3 and 17). At the same time, the social role of corporations has always been subject to political and theoretical debate. Whereas, historically, early corporations have been granted legal personality by the political sovereign, the concept of legal personhood is nowadays founded on the principle of party autonomy.