In January 1933, the Nazi Party took control of Germany, and Freud's books were prominent among those they burned and destroyed. Freud remarked to Ernest Jones: "What progress we are making. In the Middle Ages they would have burned me. Now, they are content with burning my books." Freud continued to underestimate the growing Nazi threat and remained determined to stay in Vienna, even following the Anschluss of 13 March 1938, in which Nazi Germany annexed Austria, and the outbreaks of violent antisemitism that ensued. Jones, the then president of the International Psychoanalytical Association (IPA), flew into Vienna from London via Prague on 15 March determined to get Freud to change his mind and seek exile in Britain. This prospect and the shock of the arrest and interrogation of Anna Freud by the Gestapo finally convinced Freud it was time to leave Austria. Jones left for London the following week with a list provided by Freud of the party of émigrés for whom immigration permits would be required. Back in London, Jones used his personal acquaintance with the Home Secretary, Sir Samuel Hoare, to expedite the granting of permits. There were seventeen in all and work permits were provided where relevant. Jones also used his influence in scientific circles, persuading the president of the Royal Society, Sir William Bragg, to write to the Foreign Secretary Lord Halifax, requesting to good effect that diplomatic pressure be applied in Berlin and Vienna on Freud's behalf. Freud also had support from American diplomats, notably his ex-patient and American ambassador to France, William Bullitt. Bullitt alerted U.S. President Roosevelt to the increased dangers facing the Freuds, resulting in the American consul-general in Vienna, John Cooper Wiley, arranging regular monitoring of Berggasse 19. He also intervened by phone call during the Gestapo interrogation of Anna Freud.