The Constitutum Constantini is the most famous forgery in the history of the papacy. This document, attributed to Emperor Constantine and addressed to Pope Sylvester i during the fourth consulate of Constantine (315) and that of Gallicanus (317), is divided into two distinct parts, called by modern critics the confessio and the donatio. The first part (confessio) relates Constantine's healing, conversion and baptism by Sylvester; in the second part (donatio) the emperor transfers to the bishop of Rome and all his successors primacy over all Christian churches and gives him, in addition to the imperial insignia, all power over Rome, Italy and the western regions. It is usually claimed to have been written in the second half of the eighth century on the basis of linguistic similarities with letters of Pope Paul i (757–67) and Pope Hadrian i (772–95). The most recent study devoted to the Constitutum Constantini is that of Florian Hartmann in Hadrian I (772–795): frühmittelalterliches Adelspapsttum und die Lösung Roms vom byzantinischen Reich (Päpste und Papsttum xxxiv, 2006), 182–93, who treats it as a Roman work compiled in the context of the independence of Rome from the authority of the Byzantine emperor in the second half of the 770s. Johannes Fried, professor ordinarius at the Johann Wolfgang Goethe University of Frankfurt-am-Main, offers a fresh view of the composition and reception of this forgery. He first insists on an essential distinction between the Constitutum as a document and the Donation of Constantine as an event in the collective memory of the west (chs ii, iii). He then proceeds to interpret the transfer of the western provinces of the Roman empire to Sylvester's potestas et ditio as the emperor's grant of episcopal ecclesiastical but not secular authority over areas which had previously been exempt (p. 42). He suggests also that the grant of secular authority was restricted only to the city of Rome or perhaps to the Roman duchy (pp. 47–8). He argues that the forger lacked any intimate knowledge of the Roman Church (p. 63), but finds a number of references in the text which to him suggest a Frankish origin. The first manuscript authority for the Constitutum is two-fold – in copies of the Pseudo-Isidorean decretals of around 850, and in a late ninth-century copy of a formulary of St Denis which contains no documents later than the abbacy of Fardulf (d. 806). The formulary copy has some apparently better readings than that of Pseudo-Isidore, and Fried's arguments for treating its origins as relatively late seem less than compelling (p. 72). Finally, he sees the origin of the Constitutum in the Pseudo-Isidorian forgers' workshop in the monasteries of St Denis and Corbie around 830/33, or soon thereafter. He argues that it was deployed to support Pope Gregory iv against the attacks of adherents of Louis the Pious (pp. 108–9). The first appendix contains a contribution by Wolfram Brandes on the usage of the term ‘satraps’, supporting Fried's localisation of the forgery. In the second appendix all relevant texts are printed in Latin and in English translation. This book could be characterised as a collection of lectures with a stimulating discussion of individual and collective memory on the Donation of Constantine and the origin of the Constitutum. However we are still far from a definitive account of the origin of the Pseudo-Isidorian forgeries, as pointed out most recently by Horst Fuhrmann (MGH, Studien und Texte xxxi, 2002, 227–62, esp. pp. 257–8). One should also take into account four genuine letters of Pope Vitalian from 668, known only from Pseudo-Isidore but probably drawn directly from their Roman source in the 860s (ibid. 241 n. 34, 245). Fried has not settled the argument, but he makes an important contribution to a debate which will long continue.