This is the first study of the reception of the apocryphal Second Book of Esdras (4 Ezra) from the fifteenth to the eighteenth century. Professor Hamilton discusses the concepts of biblical apocrypha and canonicity in connection with the increasingly critical attitude to religious authority which developed with the humanists and intensified with the Reformation. The Book owed its initial success to Hebraists such as Pico della Mirandola and Bibliander. It was used to account for the origins of Jewish Kabbalah and to prophesy political and religious events: the fall of the Ottoman empire, or the destruction of the papacy. Anabaptists, dissident Protestants of various persuasions, Rosicrucians and Paracelsians consulted it not only as a work of prophecy but, it is argued, as an emblem of dissent, rejected by the official Churches. At the same time more sober scholars, both Protestants and Catholics, scrutinized 2 Esdras with greater objectivity, endeavouring to date it correctly and establish its authorship. This study also investigates the interaction between their views and those of the Book's enthusiastic supporters.