Eric Knibbs has produced a book that would have brought a smile to the face of Jean Mabillon who gave modern diplomatics its shape and focus. Although scholars read documents for more than an effort to distinguish the true from the false (discrimen veri ac falsi), the search for authenticity is still at the heart of the discipline. Knibbs has tackled the mysterious origins of the peculiar double archbishopric of Hamburg-Bremen. The northern missionary Ansgar (801–865) joined Archbishop Ebo of Reims in the late 820s in the mission to Denmark and Sweden. Eventually he took over the mission in 834 when Ebo fell from power after joining the rebellion against Louis the Pious. Amid the divisions of the Carolingian Empire after Louis's death in 840, Ansgar's mission collapsed but he struggled on and in an effort to preserve its work. He forged and interpolated a dossier of documents that attempted to date the foundation of the archbishopric of Hamburg, and to assign Bremen to Hamburg, in 831. In the 870s, Rimbert, Ansgar's associate and eventual successor, wrote the Life of Anskar which itself is a powerfully deceptive account of the northern mission and the episcopal foundations. In the tenth century Ansgar's dossier was amplified. A later Life of Rimbert added new falsehoods to the story and the documentary record was further embellished in the late eleventh century and again in the twelfth. Knibbs, following a host of other scholars writing over last two centuries, unravels the threads in this spectacularly complicated story. He does a superb job of placing the whole tangled mess into the context of the political and ecclesiastical struggles of the ninth century. In addition to discerning the authentic and falsified elements in several papal privileges and in an imperial immunity diploma, Knibbs gives Rimbert's Life of Ansgar a close reading that it itself a significant contribution to Carolingian hagiography. The book is not an easy read because, studded with the technical jargon of diplomatics, it painstakingly works its way through one document after another. The reader appreciates Knibbs's clear introduction, helpful summings-up of individual sections, and excellent conclusion.
It is impossible in a review to summarize Knibb's necessarily long and detailed assessments of all the documents. Let me, then, summarize his major conclusions for they will be of greatest interest to students of early medieval church history.
From 826 to 829 Ansgar worked as a teacher in the company of Harald Klak of Denmark. In 829 Anagar went to Sweden and in 831 Gregory IV issued a legatio privilege for him. By around 831 Ebo of Reims had taken a backstage role in the northern missions; Ansgar worked in Sweden and Ebo's protégé Gauzbert worked in Denmark. Ebo was deposed in 834 after taking part in an uprising against Louis the Pious and Louis reorganized the mission. Ansgar was made a bishop at the hand of Louis's archchaplain and half-brother Drogo of Metz and he was assigned a monastery at Turholt to provide revenues to support his work; Louis equipped the monastery with an immunity. Ansgar and Gauzbert worked independently for some years, but the mission was unsettled by the political divisions of the Carolingian Empire. Ansgar lost Turholt in 843 and in 845 Vikings razed Hamburg, whose castellum and small church had provided his base of operations. Bishop Leuderich of Bremen died in 845 and Ansgar saw this as an opportunity to lobby for a bishopric at Hamburg. To facilitate his plan he began his campaign of forgeries, which claimed that Charlemagne originally planned for a bishopric beyond the Elbe and that its origins were wrapped up in documents from 831. Ansgar had little luck with his documents at church councils in 848 and 848 and meanwhile Louis the German made Ansgar bishop of Bremen and Gauzbert bishop of Osnabrück, both of them suffragans of Mainz. Louis was attempting to limit the authority of the archbishop of Cologne in the northeast because that province was under the control of his brother Lothar I and then of his nephew Lothar II. Gunthar of Mainz was deposed by Nicholas I and Lothar died childless. In the midst of these developments, Nicholas issued a privilege, modeled on that of Boniface in the eighth century, and made Ansgar, then bishop of Bremen, missionary archbishop for the Danes and Swedes. Anagar, for the first time, received a pallium and his legateship was renewed. At this point Ansgar circulated his doctored privileges but to little effect except that Nicholas made him archbishop of Hamburg based apparently on Ansgar's fictions. He died in 865. Before 876 Rimbert wrote his Life of Ansgar and portrayed him as archbishop of Hamburg from 831 with authority over Bremen. Rimbert succeeded him as archbishop of Hamburg, to be followed in turn by Adalgar. When Vikings again made Hamburg untenable, Adalgar moved to Bremen and this opened a long quarrel with Cologne over the status of Bremen. These developments led to further papal involvement and several subsequent campaigns of forgery and interpolation. The joint see of Hamburg-Bremen was thus a product of the late ninth century, not of the 830s.
This whole complex of issues is likely to remain sub iudice for some time but I suspect that the verdict will eventually fall with Knibbs. I do wonder about two things, however: how does one explain that no prominent Frankish clerics had solid memories of all that had really happened and did not contest Ansgar's and Rimbert's fanciful claims? And why did not Popes Nicholas I, John VIII, Stephen V, and Formosus have in their own archive documents to weigh against Ansgar's fictions?
