The book provides an unparalleled account of the links that draw together the International Court of Justice and the International Law Commission, exposing the depth of the relationship between these central organs of the international legal system and its profound, unintended impact. By drawing upon historical records, as well as interviews with members of both organs, the book reveals that the original vision for interaction between the Court and the Commission has been lost in time. It inquires not only into the cross-fertilization that may be traced in the output of each body but also into the more subtle ties that they nurture; it also shows how even the rare occasions of disagreement attest to the strength of the inter-institutional relationship rather than undermine it. All this throws light on the largely intangible process of international law-making and challenges the notion that international legislation is the sole preserve of States.