Hierarchy of the Sources of International Law

Broadly speaking, the ICJ will resort to the following sources for deciding a dispute before it: treaties (conventions); custom; general principles of law; judicial decisions; juristic work on international law (the teachings of publicists); principles of equity and ex aequo et bono; General Assembly and Security Council resolutions and practices. Whereas treaties, custom, and general principles of law are the main sources of international law, judicial decisions and juristic work on international law fall into the category of subsidiary sources.

Accordingly, the sources of international law will be explained under the following headings below:

1. Custom
2. Treaties
3. General principles of law
4. Subsidiary sources

5. Other sources