th Rüdiger Wolfrum celebrated his 65 birthday on 13 December 2006. On this special occasion, current and former members of the large circle of his PhD and post-doctorate students (Doktoranden und Habilit- den) organized a symposium on the subject of “International Law - day: New Challenges and the Need for Reform?” to honour him and his academic work as a teacher and researcher. The symposium took place at the Max Planck Institute for Comparative Public Law and - ternational Law in Heidelberg on 15 and 16 December 2006. Since Rüdiger Wolfrum is a renowned scholar in many different fields of public national and international law, the subjects covered by the speakers and commentators reflect the wide variety of issues he worked on in his long and impressive academic career. They extend from a cri- cal evaluation of the new responsibility to protect and the role of the UN Security Council in post-conflict management, thoughts on the proliferation of international tribunals with regard to the unity or fragmentation of international law, marine genetic resources in the deep sea and environmental protection in Antarctica to human rights issues relating to intellectual property rights and the protection of minorities. All the presentations focused on new trends in international law and thus followed the lead of Rüdiger Wolfrum who has always been at the forefront of innovative legal developments.