J. S. Castrén, Erik Keywords: State succession | Mots clefs: Succession d états | ABSTRACT Erik Castren points out that legal succession occurs in large measure and in many different forms in the internal affairs of a State. The cases of real legal succession involving the States, which are the principal subjects of international law, on one hand, are rarer and appear in less varied forms, and on the other hand, are of a much larger order of magnitude. After presenting various fundamental issues, the author gi…