The IHEI was established by a decree of July 30, 1920 and inaugurated on April 19, 1921 during a solemn ceremony attended by the President of the Republic, Alexander Millerand.
The IHEI was founded with an attempt to uphold post-war expectations to maintain the new international legal order with the help of international law instruments. Namely, the main goal of the newly established League of Nations and the Permanent Court of International Justice was believed to be a contribution to the world peace. It is in this spirit that institutes dedicated to education and research in international law were created in Europe and in the Unites States, among which is the Graduate Institute of International and Development Studies in Geneva, founded in 1927.
Throughout its history the IHEI in Paris has been directed by leading academics of international law in France . The Institute was founded by Paul Fauchille and Albert de Lapradelle – further also Alejandro Alvarez (Chili), as well as by Gilbert Gidel, Marcel Sibert, Charles Rousseau, Prosper Weil, Jean Combacau, Pierre-Marie Dupuy, Charles Leben, and Joe Verhoeven. Currently the IHEI is led by Professor Carlo Santulli, who is also the Director of the Editorial Board of the Revue Générale de Droit International Public (RGDIP).
Most of the invited French and foreign academics and practitioners are themselves former students of the IHEI. Such authors as Christian Paul Fauchille, Marcel Sibert, Maxime Chrétien, Georges Scelle, Louis Cavaré, Paul Reuter, Charles Rousseau, Jean Combacau, Pierre – Mary Dupuy, Joe Verhoeven and Carlo Santulli as well as other former IHEI students contributed to the publication of several collection of courses as well as monographs in international law.