International custom "as evidence of a general practice accepted as law", is considered one of the two main sources of international law as it primarily derives from the conduct of sovereign States, but is also closely connected with the role of the international judge when identifying the applicable customary rule, a function it shares with the bodies in charge of its codification (and progressive development), starting with the International Law Commission. Though mainly considered to be general international law, international custom has a complex relationship with many specific fields of law and specific regions of the world. The editor provides comprehensive research published in the last seven decades, invaluable to everyone interested in the field of customary international law.