The Vienna-born art historian Fritz Saxl was awarded his doctorate from the University of Vienna in 1912 for a thesis on Rembrandt van Rijn. He met the art historian Aby Warburg (1866–1929) in 1911 and in 1914 became a research assistant in the cultural library in Hamburg founded by Warburg. After a break on account of the war from 1915 to 1918 and his subsequent work in adult education, he resumed there in 1920 as provisional director. In subsequent years he was instrumental in developing the library into a research institute devoted to art and culture. After Warburg's death in 1929, he became director of the library. In 1933 he was forced to emigrate from Hamburg to London due to persecution by the Nazi regime as a Jew. His wife Elise (née Bienenfeld), whom he had separated from in 1920, also emigrated to London in 1934. Their children Hedwig and Peter started studying in Scotland and London. He had managed as director of the library to have its contents shipped from Hamburg to British exile. With the support of the Warburg family and British art historians, over 55,000 books, the photo collections and inventory were transferred in December 1933, ostensibly as a loan to the University of London. In May 1934, the library reopened in London with the name Warburg Institute. Gertrud Bing (1892–1964) was appointed deputy director of the Institute and was its director from 1955 to 1959. Saxl and Bing sought to assist persecuted colleagues from continental Europe, such as Ernst Gombrich (1909–2001), who emigrated to London in 1936 and was later director of the Warburg Institute. They also expedited the release of émigrés, such as Ludwig Münz (1889–1957), a Viennese art historian and student of Saxl, who had been interned by the British authorities as enemy aliens, despite their status as refugees from the Nazi regime. In 1944 the Institute was integrated into the University of London. Saxl remained its director until his death in 1948.
In the course of provenance research at the library of the University of Vienna, a printed document with the stamp Fritz Saxl was found. The dissertation Iconography of the Seven Planets in Medieval Italian Art by Bruno Archibald Fuchs (1881–1921) from the year 1909 highlights Saxl's interest in astrology and antique and medieval astrology, which he shared with Aby Warburg. As the library of the University of Vienna could not be demonstrated to have acquired the document legally, it was restituted in 2014 to Fritz Saxl's legal successors.