or Faculties, were Law and Political Science, Medicine, Philosophy and Natural Sciences. Weimar Republic and the National Socialist Era During the Weimar Republic, the university quickly grew to become important. The student population reached several thousand, and the growing popularity of the university drew scholars such as Albrecht Mendelssohn Bartholdy, Aby Warburg and Ernst Cassirer to Hamburg. Many students were suffering due to the poor economic situation that prevailed in the early republic, leading to the foundation of the Hamburg Association of Student Aid in 1922. Ernst Cassirer became the principal of the university in 1929, one of the first Jewish scholars to take that role in Germany. The number of full professors had grown to 75 by 1931. The academic situation shifted quickly after the general election in March 1933. On 1 May of that year, the university held a ceremony to honor Adolf Hitler as its leader. Massive political influence by the Nazis followed, including the removal of books from the libraries and harassment against alleged enemies of the regime. About 50 scientists, including Ernst Cassirer and William Stern, had to leave the university. At least 10 Hamburg students were suspected of working with the White Rose and arrested; four died in custody or were executed. A commemorative plate depicting the foyer of the lecture hall, designed by Fritz Fleer, was produced in 1971 in their memory. In the Federal Republic of Germany Once the Second World War was over, the university reopened in the winter of 1945 with 17,800 employees. Of the 2,872 students who were enrolled at the University of Hamburg in the first postwar semester of 1945/46, 601 had been admitted to the School of Philosophy, 952 to the School of Medicine, 812 to the School of Law and Political Science, and 506 to the School of Mathematics and Natural Sciences. The first student association during this period was elected in 1946 under British supervision, and it became the foundation of the General Students' Committee, AStA, in 1947. During the West German era, new departments were added to the university. In 1954 the School of Protestant Theology was added, and the School of Law separated from the School of Economic and Social Sciences. This growth was accompanied by significant construction in the late 1950s and early 1960s. The Auditorium and the Philosopher's Tower were inaugurated near the Von-Melle-Park, while the Botanical Institute and Botanical Garden