Sources of International Law

The sources of international law regulate how international rules are made. Article 38 of the ICJ Statute has traditionally been seen as the starting point for an exploration of the sources of international law, famously referring to three sources: treaties, custom, and general principles. However, to fully understand the doctrine of the sources, it is necessary to look beyond article 38. For example, the practice of international actors has furthered the theory of these sources and there is growing academic support for the development of international law beyond these categories. The aim of this chapter is to introduce the different sources of international law and the relationships between them.