This "Liber Amicorum" is published at the occasion of Judge Lucius Caflisch's retirement from a distinguished teaching career at the Graduate Institute of International Studies of Geneva, where he served as Professor of International Law for more than three decades, and where he has also held the position of Director. It was written by his colleagues and friends, from the European Court of Human Rights, from universities all around the world, from the Swiss Foreign Affairs Ministry and many other national and international institutions. The "Liber Amicorum Lucius Caflisch" covers different fields in which Judge Caflisch has excelled in his various capacities, as scholar, representative of Switzerland in international conferences, legal adviser of the Swiss Foreign Affairs Ministry, counsel, registrar, arbitrator and judge. This collective work is divided into three main sections. The first section examines questions concerning human rights and international humanitarian law. The second section is devoted to the international law of spaces, including matters regarding the law of the sea, international waterways, Antarctica, and boundary and territorial issues. The third section addresses issues related to the peaceful settlement of disputes, both generally and with regard to any particular means of settlement. The contributions are both in English and French.