In November 1995 I received the singular honor of being invited to deliver the George Macaulay Trevelyan Lectures at Cambridge University in the Lent Term of 1999. I deeply appreciated the opportunity given me by the Electors to present the twentieth set of biennial lectures in this very distinguished series that began in 1959. But I must admit to some initial trepidation, for the letter of invitation indicated that the lectures were intended to commemorate Trevelyan by attending to aspects of history that interested him. Trevelyan was at home in the seventeenth, eighteenth, and nineteenth centuries. He wrote broad synthetic national histories that focused on the emergence of a distinct English political culture marked by liberty, civility, decency, and moderation on the one hand and heroic biographies of figures he deemed exemplary and inspirational on the other. In contrast, he wrote of the twentieth century: “I don't understand the age we live in and what I do understand I don't like.” That was in 1926, and the following decades were even more disagreeable. Moreover, my own subject was to be the most tragic and terrifying event of those terrible decades. But Trevelyan also believed that history had a public function – to instruct about the frailty of the human condition and the necessity for civic virtue. In this regard, at least, I hope that he would not consider lectures addressing the topic of the Holocaust an inappropriate commemoration of his legacy.