The Charité complex (Universitätsklinik Charité) is the largest university hospital in Europe, tracing back its origins to the year 1710. More than half of all German Nobel Prize winners in Physiology or Medicine, including Emil von Behring, Robert Koch and Paul Ehrlich, have worked at the Charité. The Charité is spread over four campuses and comprises around 3,000 beds, 15,500 staff, 8,000 students, and more than 60 operating theaters, and it has a turnover of two billion euros annually. The Charité is a joint institution of the Freie Universität Berlin and the Humboldt University of Berlin, including a wide range of institutes and specialized medical centers.