Friedrich "Fritz" Saxl was raised in a secular, culturally-Jewish home. He studied art history at the Institut für Österreichische Geschichtsforschung (Institute for Austrian Historical Research) under the Vienna School art historians Franz Wickhoff, Julius von Schlosser and Max Dvořák, who oversaw his dissertation on Rembrandt. In 1911, he met the private scholar-art historian Abraham "Aby" Warburg. Saxl went to Berlin for further study, and spent 1912-1913 doing research in Italy for his only major book, a study of medieval illuminated manuscripts with astrological and mythological elements. In 1913, he married Elise Bienenfeld and joined what was then called the Warburg Library in Hamburg as librarian. He served as an officer in the Austro-Hungarian Army in World War I, and returned to the Warburg in 1919. In addition, he lectured at the University of Hamburg from 1923. Prof. Saxl helped transform the library into a scholarly institution. On the death of Aby Warburg in 1929, Prof. Saxl formally became director, although he had effectively been in charge for several years already due to Warburg's illness. When the Nazi regime came to power in Germany in 1933, Prof. Saxl and his partner Gertrud Bing arranged with the Courtauld Institute of Art to move the enormous library of books and photographs, archives, and other resources of the Warburg Institute to safety in London. He settled in England himself and became a British citizen in 1940. His work to maintain the Warburg Institute came at the cost of his own scholarship, which was mostly limited to papers and lectures. In 1944 the Warburg Institute was officially made part of the University of London.