Professor Wilfried Hartmann’s meticulous new edition of Regino’s rich and engaging text marks an appropriate start to this new, if long overdue (it was first suggested in 1914), MGH series of canon law collections. The significance of Regino’s work has long been recognised by scholars of canon law, not least because Burchard of Worms drew on it for just over one-third of the texts in his Decretum. In more recent years the fact that Regino’s compilation drew so heavily on Carolingian materials and was framed around the bishop’s visitation of a local church, being divided into two books focused around the behaviour of the clergy and the laity, has attracted historians interested in tracing the histories of episcopacy and pastoral care in the post-Carolingian age.

Regino’s work was popular in tenth- and early eleventh-century Germany and Lotharingia. It survives in eleven complete manuscripts (four of the »genuine«, seven of the »interpolated« or rather lightly revised text) and four fragments. References in medieval book lists refer to a further eleven manuscripts, now lost. Up until now scholars have had to rely on Friedrich Wilhelm Hermann Wasserschleben’s 1840 edition if they wanted access to the whole of this text: for reasons of space, Professor Hartmann’s own interim revision and translation of Wasserschleben’s edition published by Wissenschaftliche Buchgesellschaft in 2004 frustratingly omits around 20 % of Regino’s text (169/921 chapters), together with all the appendices identified in the manuscripts by Wasserschleben. But the MGH edition now provides us with access to the entire text, accompanied by a parallel German translation. For the first time scholars can follow Regino’s text across different manuscripts in a way which simply has not been feasible hitherto.

Hartmann is scrupulous in acknowledging the strengths of Wasserschleben’s edition: he follows Wasserschleben in dividing the manuscripts into two groups, and using the chapter numbers in the two earliest manuscripts of the »genuine version«. But Wasserschleben muddied the waters by including his own cross references between different chapters: one of Hartmann’s many achievements is to identify those cross references which are found in the genuine version and seem to be original to Regino’s text, such as that between Book I, 212 on how the priest should take care of guests by providing them with food and shelter and Book II, 428 on how all parishioners should be hospitable and deny a place of rest to no traveller. Here we begin to see Regino’s working methods and interest in tracing themes across the different books on clerical and lay behaviour.

Where Hartmann departs much more substantially from Wasserschleben is in the careful way he has unravelled the complex manuscript history of the texts found alongside Regino’s collection and which Wasserschleben published as three appendices. Instead of Wasserschleben’s three appendices of canons he has identified some nine different appendices in the manuscript tradition, and distinguishes between those which constitute later additions by Regino from those made by later readers. Wasserschleben thought only »Appendix I« was original to Regino. Hartmann refines this further. He agrees that cc. 1–20 of Wasserschleben’s »Appendix I« are likely to be part of Regino’s original work; they are all found in the three complete manuscripts of the »genuine« tradition, as well as seven in the interpolated version, and draw on the same authorities as Regino did elsewhere (Hartmann’s »Appendix A«). Hartmann further argues that cc. 21–26 of Wasserschleben’s »Appendix I« (his »Appendix B«) also probably came from Regino’s scriptorium, highlighting how c. 21 (which draws on the Theodosian Code) on the proper process for accusing someone in court summarises the argument of the other canons in »Appendix B«; they are all to be found in two manuscripts of the »genuine« version as well as seven of the interpolated version. The canons in Hartmann’s »Appendix C« (Wasserschleben’s »Appendix I«, cc. 27–28) are to be found in all the interpolated manuscripts but not those of the genuine version. Hartmann’s »Appendices D« to »K«, by contrast, each of which is found in at least one but no more than three of the interpolated manuscripts, seemingly reflect not so much Regino’s »afterthoughts« but rather readers’ responses to the text itself.

Building on his research into Regino published over the last thirty years, Hartmann’s careful identification of all the sources for Regino’s texts allows him to highlight not only Regino’s authorities but also further investigate his working methods. Hartmann is not merely content with demonstrating that Regino drew on two earlier ninth-century Carolingian collections of early church law, the Dacheriana and Quadripartitus, for some 271 out of his 456 chapters. Rather, he points out how there are surviving ninth-century manuscripts which combine these two collections, and how a similar compilation may have served as Regino’s source. Carolingian penitentials – especially the Paenitentiale mixtum Pseudo Bedae-Egberti – supply about one-fifth of the texts in Regino’s collection. But the Carolingian councils provide over one-third: something which Regino himself recognised as unusual and defended in his dedicatory letter to Archbishop Hatto of Mainz on the grounds of their relevance to »these dangerous times«. No one is better placed than Professor Hartmann to investigate Regino’s working methods here, but the problems of survival make it impossible, leading him to admit that it is neither clear quite what guided Regino’s choice of councils, nor whether they all came from a single, now lost, manuscript. Finally, 92 out of Regino’s 456 chapters have no known source at all: these include forms for conducting an inquisition, various oath formulae, excommunication formulae, forms for conducting manumissions and form letters for priests moving between dioceses. Elsewhere Hartmann and others show how many of these unknown texts accord with other evidence from the ninth century. Taken together, his work confirms how the collection of Regino the canonist was a product of Carolingian knowledge and practice.

Through his excellent research Professor Hartmann has done much more than put future studies of Regino the canonist on a firm footing: he has set out the blueprint for the standard to be followed by others in future volumes in this series.