In its process of international legal recognition, human dignity came to nuance, then influence and, ultimately, fundamentally transform the very architecture of international law. In a lapse of time of about a century and a half, important historical changes brought human dignity to the center of international law and upset the rules governing relations between States, and, above all, between States and individuals. The dignity of the human person has been increasingly seen as an antidote against the abuse of sovereign dignity. Yet, what is remarkable is the choice of the concept of ‘dignity’, out of so many other concepts, to assert the normative claim of a value against another. This thesis explores the conceptual battlefront opened by the concept of human dignity and examines when, where and how this development occurred and with what implications. It concludes that human dignity, first in its religious and then in its secularized conception, was turned into a platform against sovereign dignity that would in time conquer, through a range of legal instruments, vast sways of international law where sovereign dignity previously rule unchallenged. This thesis therefore aims to understand the roots of the idea of dignity and, subsequently, reconceptualize it within the language of international law.