Along with treaties, international cases are some of the most important documents of international law.
The primary source of international case law is the International Court of Justice (ICJ), a part of the United Nations. Its predecessor, the Permanent Court of International Justice, rendered decisions from 1922-45. The current court started in 1945 and is based in The Hague.
Other sources of important international case law include the European Court of Justice (ECJ), and European Court of Human Rights (ECHR).
The International Court of Justice (ICJ) decides cases of international law between separate countries and it issues advisory opinions on legal questions referred to it by the UN. Cases from 1947-present available on Westlaw, Lexis, and for free on the ICJ website (PDF). The court’s website also contains oral proceedings and other court documents.
European Court of Human Rights (ECHR): The ECHR is the result of the European Convention on Human Rights and is administered through the Council of Europe. The ECHR is separate and distinct from the European Court of Justice (ECJ). Cases from 1960-present are available on Westlaw, Lexis, and for free on the ECHR's website.