The analysis of forgery has been at the heart of the medieval historical enterprise since its first beginnings as a scholarly discipline. For the early pioneers the detection of forgery was the prerequisite of any empirical enquiry, and for some the formulation of a subdiscipline in which to achieve it – the ars diplomatica – soon superseded it as their principal scholarly objective. The prevalence of the diplomatic perspective, which privileges a binary opposition of true and false, Alfred Hiatt argues, has obscured the extent to which forgery was in fact to be found in the mainstream of textual production, as it were, as an extension, or exaggeration, of its inherent techniques and tendencies, its ‘ordinary principles’, as he terms them. Hiatt advances his alternative view of strategies for the (mis)-representation of authority in a series of cases studies of clerical communities – regular and secular – in fifteenth-century England. The ‘golden age’ of forgery in England is generally understood to be the century following the Conquest, when (especially) monastic communities struggled to survive the transition from a tenurial tradition founded on oral and visual proofs to one vested only in written documentation. As ecclesiastical and secular institutions embraced the written word over the course of the next two centuries, however, Hiatt contends that there was no corresponding decline in clerical compilers' recourse to forgery. In fact, in the early years of the fifteenth century, in a climate of intense political uncertainty, as the Lancastrian regime confronted recurrent rebellions and rumours of a Ricardian revival, the compulsion to manipulate textual authority may have been as powerful as it was to any writer of the post-Conquest generation. A measure of this might be seen, Hiatt suggests, in the statute against forgery issued early in the reign of Henry v (1413). Hiatt's case studies concern three constituencies of clerical England: the historical compilations of the Benedictine monks of Crowland Abbey (Lincolnshire), made in the first and second quarter of the fifteenth century, suggest that the misrepresentation of authority had lost none of its appeal – or institutional importance – for the past masters of the art. The monks repackaged the forgeries of earlier periods into a continuous chronicle narrative, the centrepiece of which was represented as the work of one Ingulf, a voice of apparently unimpeachable authority on the abbey's Anglo-Saxon past. The scale and skill of their historical creation is at least comparable, Hiatt suggests, to the work of the better known Benedictine chroniclers of Bury St Edmunds and St Augustine's, Canterbury. Hiatt's second case concerns the secular clerks of the University of Cambridge from whose midst emerged two equally audacious examples of fifteenth-century forgery, a pair of papal privileges, purporting to be of Honorius i and Sergius i (dated 624 and 699 respectively), providing an early exemption from even metropolitan jurisdiction, and the Historiola, or De antiquitate et origine alme et immaculate universitatis Canterbrigie, the first history of the university, which interspersed a mythological narrative of foundation with further forged documents, among which was a charter of King Arthur. Hiatt interprets these as an instance in which forgery served not to subvert authority but rather, properly, to reinforce it, since no part of the text misrepresented conventional views of the university and its origins; he also observes that the claims of Cambridge were part of a wider, pan-European mythology of the studium in a century which saw the establishment of more than two dozen new, and vulnerable, studia generales. In his third case study Hiatt turns from institutional to individual forgery. John Hardyng, former soldier and servant of the Lancastrian crown, produced at least twenty forgeries documenting the supposed submission of the Scots to the English crown. This diplomatic project interlocked with the work for which he is best known, his verse chronicle, in which he further advanced his counter-factual of Anglo-Scottish relations expressed both verbally and visually in a map of Scotland. His mapping, Hiatt suggests, is an extension of the same impulse that inspired the Cambridge clerks and the Crowland monks, that is to possess documentary authority that bears visual and well as verbal power. In the closing chapters Hiatt considers the continental context, where Valla's exposure of the Donation of Constantine, he argues, represented a new departure in the ‘discourse’ of forgery, since the application of the term to the apocryphal held major implications for a range of texts and relics. Here Hiatt demonstrates the continuing power, provocative and restorative possibilities of forgery even (or perhaps especially) in the cultural flux of late medieval Europe as well as the formative role it played in the making of post-medieval, and modern, historiography.