This edition presents the first scholarly edition of Robert Southey’s various writings about the prophetic movements of Romantic-era Britain. Its aim is to throw new light on two related areas: the nature and history of millenarian prophecy in the late eighteenth and early nineteenth centuries—especially William Bryan, Richard Brothers, and Joanna Southcott—, and the significance of prophecy in Southey’s social, political analysis of his times. A fascinated commentator upon what he termed ‘enthusiasm’, Southey published two of the earliest accounts of Southcott and her predecessors ever written, accounts derived both from personal acquaintance with some of the major figures involved and from a detailed study of their writings. These accounts are reproduced here, collated with the manuscripts on which they were based, and with explanatory notes. In addition, a selection of Southey’s remarks on millenarians in his private manuscript correspondence is presented, and an introduction comprising a brief history of the prophetic movements in the Romantic era and a critical discussion of Southey’s writings on the subject.