This Liber Amicorum is dedicated to one of the most outstanding international lawyers, Professor Seidl-Hohenveldern, in celebration of his eightieth birthday. Professor Seidl-Hohenveldern is known throughout the academic world for his profound contributions to the theory and practice of international law. He has also acted as arbitrator in a number of international cases and was President of the UN Conference on State Succession in respect of State Property, Archives and Debts. The contents of this Liber Amicorum reflect the broad activities of Professor Seidl-Hohenveldern, both in his academic and practical work. The fields covered include: - international public law; - international private law; - international economic law; - international human rights law; - international environmental law; and - European law. The contributions, from well-known authors worldwide, display an interesting and valuable spectrum of the current state of the law. Thus, the work covers a wide range of different topics of international law and different positions on developments in recent years.