The ERC-funded project on Agency in Law (LEGACY) probes and problematizes the legal notion of agency, deeply embedded in Western legal systems and situated within a liberal tradition of political and legal philosophy. In this view, legal agency – the capacity to be held responsible and to perform legally valid acts – has been reserved for adult human beings deemed to be of sound mind. Liberal Agency has recently come under increasing criticism and challenges. Many now argue that persons with disabilities, children, artificial intelligence systems and/or nonhuman animals could in fact be treated as agents. The main aim of LEGACY is to achieve a comprehensive, rigorous, and historically informed understanding of legal agency. This overall understanding will be reached by accomplishing three objectives. The first objective is the creation of a historical account of the birth, development and spread of Liberal Agency in law, as well as its historical challengers. The second objective is to scrutinize legal agency in the contemporary context through thematic analyses of agency. Finally, LEGACY will develop a completely new theory of legal agency that provides an overall synthesis of the different accounts and can explain, reconcile and/or solve the contemporary challenges to our understanding of agency.