When writing about the tenth-century ecclesiastical reform in England thirteen years ago, Eric John rightly pointed out that ‘the tenth and early eleventh centuries are the least studied and most taken for granted periods of both English and Continental history’. But today, this contention is no longer true: investigation into different aspects of the monastic revival has resulted in a considerable number of special publications. In particular, the millennial celebrations marking the deaths of the leading reformers, Æthelwold (d. 984), Dunstan (d. 988) and Oswald (d. 992), have been accompanied by a reassessment of their activities and achievements, the fruits of which are assembled in three collections of essays by experts in a variety of fields. The renewed interest in the reform era has naturally drawn scholarly attention to the primary sources which provide first-hand information about the thought, aims and strategies of the reformers. Among such documents, the Regularis Concordia (henceforth RC) plays a major part as an object of historical and liturgical research; besides, it has turned out in recent years that the Latin text and especially the Old English interlinear gloss of the consuetudinary also offer important material for the philologist and the historical linguist.