This thesis aims at the resolution of a dilemma which has been bothering international lawyers for at least two decades, namely whether armed intervention as a response to gross and massive human rights violations is ever legally justified without the authorization by the Security Council pursuant to Chapter VII of the United Nations Charter. Thus far, international lawyers may be said to have been caught between giving a negative answer on the basis of the rules in the Charter, and a ‘turn to ethics’, i.e. declaring humanitarian intervention legitimate on moral grounds, while leaving questions of legality to the side. These two camps may be termed ‘positivists’ and ‘moralists’ respectively. In this thesis, a third solution to this dilemma is proposed. The idea is presented that many equitable principles may qualify as ‘general principles of law recognised by civilised nations’ – the third principal source of international law, a conclusion based upon detailed research of both national legal systems and the international legal system itself. These principles, having normative force in international law, are then used to craft an equitable framework for humanitarian intervention. It is argued that the dynamics of their operation allow them to interact with the UN Charter regime and customary international law in order to fill gaps in the existing legal structure and soften the rigours of strict law in extreme circumstances. It is asserted that many of the arguments of the moralists are justified, albeit based upon firm legal principles rather than ethical and philosophical theory. The equitable framework proffered in the final chapter is designed to provide an answer to the question of how the concept of humanitarian intervention may be integrated into the realm of law. Certainly, this will not mean an end to controversies regarding concrete cases of humanitarian intervention. However, it will enable the framing of such controversies in legal terms, rather than as a choice between the law and morality.