Freie Universität Berlin was founded on December 4, 1948, by students, scholars, and scientists with the support of the American allied forces and politicians in Berlin. Students and academics wanted to be free to pursue their learning, teaching, and research activities at Freie Universität, without being subject to political influence. To a large part, the founding can be credited to the efforts of then-mayor Ernst Reuter.

Every year, Freie Universität therefore celebrates its founding with the so-called Ernst Reuter Day. The university community, alumni, friends, and supporters of the university come together to celebrate this day.

On this occasion, Freie Universität honors distinguished students and researchers for their work. Most notably, the Ernst Reuter Prize, endowed by the Ernst-Reuter-Gesellschaft, is awarded to young scholars and scientists at Freie Universität for outstanding disseration projects. The incoming scholarship recipients and supporters of the Deutschlandstipendium are also welcomed during the official program.

Following the official celebration, honorees, current members, and alumni of Freie Universität have the opportunity to meet and reconnect during a reception.