This book deals with all the cases that came before the Permanent Court of International Justice (PCIJ) from 1922 to 1946, as well as those that were heard by its successor, the International Court of Justice (ICJ) from 1946 to 2020 in which interim measures of protection were either indicated or refused. The monograph shows how cases in which injunctive relief was sought were handled and how the PCIJ and the ICJ have undergone certain reforms over the years. The new approach taken by the author is to present all the matters brought before both the PCIJ and ICJ in full and to present the new requirements on the part of the ICJ that have been formulated in recent years. The book is aimed at law students, lecturers and those working in the field of international law. Ewa Sałkiewicz-Munnerlyn was a Polish diplomat working for the Ministry of Foreign Affairs from 1991 to 2018. She was appointed charge d’affaires at the Polish Embassy to the Holy See from 1993-1994, after which she served as the Polish consul at the Consular Division of the Polish Embassy in Washington D.C. from 1995-1999. She then held the position of Human Rights Officer of the OSCE in Macedonia (Skopje and Ohrid) and Bosnia and Hercegovina (Pale in Republika Srbska) from 2001-2005 and has also several times worked as a short-term observer of the OSCE during parliamentary and presidential elections in Ukraine, Russia, Moldova and Belarus. She attained a Ph.D. at the Jagiellonian University in Krakow, Poland and a post-graduate diploma at the Institut des Hautes Etudes Internationales in Geneva, Switzerland.