Tobias Asser was already in his seventies when he won the Nobel Peace Prize in 1911 for his work on private international law: the unglamorous business of deciding which country's rules apply when a Dutch ship docks in Argentina with a Belgian cargo. He had been agitating for an academy of international law since the 1907 Hague Peace Conference. With the prize money in hand he could finally seed the thing, and Andrew Carnegie's foundation, which had built the Peace Palace itself, agreed to make up the rest. Asser died in 1913 without seeing his school open. The opening was delayed by the First World War, the very catastrophe his discipline was meant to prevent. When the academy finally welcomed students in 1923, his portrait already hung on the wall.

The academy has no permanent teaching staff and never has. Its governing body, the Curatorium, simply picks the people most worth listening to that year: sitting judges from the International Court of Justice, foreign ministers, treaty negotiators, professors with reputations measured in continents. Twelve future judges of the World Court have lectured here. So did Boutros Boutros-Ghali, who later ran the United Nations and then returned to preside over the Curatorium. The summer courses run for three weeks in July on public international law and three weeks in August on private. Lectures are delivered in English or French, with simultaneous interpretation between the two. Students come from eighty to a hundred countries each year. Roughly one in five attends on a merit scholarship.

Since that first 1923 session, every lecture series has been published, in the language it was delivered, in a set of volumes known to international lawyers simply as the Recueil des cours. The bindings are green. The collection now runs past 440 volumes and is the single most comprehensive encyclopedia of international law in existence. A working international lawyer in 2026, anywhere on Earth, will at some point reach for a green binder from this collection. It is the academy's most concrete claim on the field: not a building, not a degree, but a continuous century-long record of what the best minds in the world thought international law should be.

Between 1915 and 1974, the academy was nominated for the Nobel Peace Prize seventy-three times. It never won. It did pick up the Wateler Peace Prize twice, the Felix Houphouet-Boigny Peace Prize once, and Brazil's Order of Rio Branco, and it carries on largely indifferent to whether anyone in Oslo notices. The Centre for Studies and Research, opened in 1957, hosts two dozen advanced researchers each August to grind through a single year's question: international migrations one year, criminal acts at sea another, the legal implications of global financial crises after the 2008 crash. The External Programme has taken the curriculum on the road to host governments in Africa, Asia and Latin America since the late 1960s. Winter Courses were added in January 2019. The COVID-19 pandemic forced the 2021 edition online, the first interruption to the in-person format since 1939.

Most days of the year the Peace Palace is the seat of the International Court of Justice and the Permanent Court of Arbitration. For six weeks of summer and a few weeks more in January, its lecture rooms belong to students. The academy's own facilities sit next to the main palace, including the Academy Hall designed by Michael Wilford and Manuel Schupp, and the Peace Palace Library, which holds one of the deepest international-law collections anywhere. Walking the same corridors as judges who rule on genocide cases and arbitrators who carve up maritime boundaries is part of the pedagogy. The current president of the Curatorium, Diego Fernandez Arroyo of Sciences Po, was elected on 24 May 2024. His secretary-general, Jean-Marc Thouvenin, has been in post since 2017. Their job, in essence, is to ensure that a century after Asser's bequest, the world keeps showing up in summer.