One small detail from a book by Cecil Roth that sticks in my mind is his description of searching antiquarian booksellers in Italy and finding incredibly valuable and sometimes unique sources of history for the books he wrote. This brought home to me what a pioneer he was in the field of Jewish history, and how times have so completely changed in the course of a century.
I have enjoyed every book by Cecil Roth that I have read, including his biographies of Dona Gracia Nasi and her nephew the Duke of Naxos, his biography of Menassah ben Israel, several of his histories of the Jews in specific cities of Italy, and others. I am aware that he was instrumental in making Jewish history part of respectable mainstream history in the refined atmosphere of British academia. And I've bought a biography of him, but I haven't read it yet, so I can't say much more. For anyone who appreciates having systematic Jewish historical books he's definitely a hero.