Published anonymously in 1733, Memoirs of the Twentieth Century is one of the earliest futuristic novels known in Anglophone and Euro-American literature. It foregrounds an acceleration of history brought about by an increasing degree of global interconnectedness, and the exclusion of prophetism and astrology as credible ways to know the future. The work of Samuel Madden, an Irish writer and philanthropist of Whig sympathies, it consists of a collection of diplomatic letters composed in the 1990s, which the narrator claims were brought to him from the time to come by a supernatural entity. Through these correspondences, twentieth-century world scenarios are spread out before the reader, in which British naval power rules the waves and international commerce, while the transnational scheming of the Jesuits threatens the independence of weaker European courts. This book - which includes a study followed by an annotated edition of the text - assesses the cultural significance of this literary work, as an apt observatory on how historical time as a cultural construction was shaped, during the eighteenth century, by new forms of transnational circulation of information, and by the dubious space carved out in European culture by seventeenth- and early eighteenth-century debates on the nature of historical knowledge. Through and by means of the Memoirs case study, this volume aims to contribute to a wider cultural history of the future and speculative fiction. The novel's ironic distancing of beliefs considered to be superstitious and absurd - such as divination techniques and occult and magical disciplines - offers an exceptional testimony to the negotiation of the boundaries of verisimilitude and credibility within a religious enlightenment.