The Episcopal Frontier
Within the organizational structure of the Christian Church, bishops are responsible for the oversight of all aspects of Christian practice for the community of believers within a defined territory, called a diocese. They are charged with consecrating churches, ordaining priests, preaching, and generally assuring that Christian observance adheres to doctrine as determined by previous church councils and the pope in Rome.
Situated from Roman times within urban centers, the existence of a bishopric attests to the presence of a community of Christians within the region. However, it by no means attests to the quality or uniformity of Christian belief among the local populace. Moreover, bishoprics can vary greatly in territorial extent, wealth, prestige, and political influence. They nonetheless lay the foundation for Christian practice and, as institutions, do so independently and beyond the lifetimes of individual bishops.
(N.B. Foundation dates are often uncertain or disputed given the scarcity of documentation surviving from these early periods. Those we provide—click on a location—derive from the scholarship but, in many instances, should be regarded as tentative.)
Map I
Map I: 650 C.E.
This map shows those bishoprics in existence by the middle of the 7th century in the region that would eventually become the east Frankish/German Empire. Many are in towns dating to the Roman era, situated on the Rhine river which (together with the Danube) formed the de facto boundary between the empire and the Germanic peoples living on the eastern bank and beyond. Some are known as sites of early Christian communities, even bishops. For others, bishops are first attested only under the Merovingian Franks, who succeeded the Romans in this region. All are bishops, not archbishops, and no hierarchical relations existed between them.
Map IIA and IIB
Map IIA: 747 C.E.
A century later, Christian belief and practice had spread beyond the Rhine and Danube and new bishoprics were established to support orthodoxy there.
Throughout this period, Christian missionaries worked actively to spread the faith among nonbelievers—and were later memorialized as saints for their commitment to evangelization. In some regions, especially Frisia and Saxony, local peoples proved hostile to their efforts and sometimes murdered missionaries, whom Christians then hailed as martyrs. Elsewhere, for instance in Thuringia and Bavaria, missionaries found that Christian belief had preceding them, with local people exposed to—and some of them espousing—Christianity as a result of routine cross-border contacts in Roman and post-Roman times.
Shown on the map here, in the mid-eighth century, through efforts conventionally associated with Saint Boniface (d. 754), bishoprics came to be founded either to structure the practice of preexisting communities or to anchor missionary work.
However, some of the latter proved ephemeral, situated in regions with inadequate numbers of Christians or lacking the support of local elites. As reflected on the second map here, the sees of Büraburg and Erfurt quickly proved untenable, as had the bishopric established among the Frisians a generation earlier at Utrecht for Willibrord, who more often made the monastery of Echternach his missionary base. Fulda functioned comparably for Boniface, and together with Hersfeld, served as the chief outposts of Christianity in the region.
Map IIB: 756 C.E.
These maps also show the establishment of a hierarchy among bishoprics, again to facilitate oversight and assure orthodoxy. Boniface himself arranged for his elevation to the rank of archbishop of Mainz and then the subordination of a majority of German sees to his authority. This disposition originally pertained only to him personally, but was institutionalized under his successor at Mainz, Archbishop Lull, in 781.
Map III
Map III: 820 CE
Around the same time that Mainz’s status was formalized, the venerable sees of Trier and Cologne were likewise elevated to archbishoprics, in 772 and 784 respectively, and assigned subordinates (called “suffragans”). In 798, the same occurred in Bavaria, with Salzburg made an archbishopric. This reorganization followed the assumption of power by the Carolingian dynasty, who replaced the Merovingians kings of the Franks around the time of Boniface, whose efforts they had supported.
This map also shows the cluster of new bishoprics established after Charlemagne’s conquest of the Saxons, who were thereby converted forcibly to Christianity. Most were founded around the year 800, with Bremen somewhat earlier, Halberstadt and Hildesheim somewhat later. In addition, by 780, a see at Utrecht had become more secure established.
Map IVA and IVB
Map IVA: 875 C.E.
These maps show two efforts to spread the Christian faith among non-Christians to the north and east of Francia in the middle of the ninth century, resulting in controversial archbishoprics.
Methodius, a missionary from Thessaloniki evangelizing—together with his brother, Cyril— among the Slavs living in the region between the Byzantine and Frankish empires, was made archbishop of Sirmium by Pope Adrian II in 969. He was responsible for the nascent Christian communities of Moravia and Pannonia—a right contested by bishops in Bavaria. The see did not endure after Methodius’ death in 885.
This period also witnessed efforts to evangelize among the Danes led by Bishop Ansgar of Bremen (d. 865), who appears to have falsely claimed that an archbishopric was established for him at Hamburg, as did his successor, Rimbert (d. 888). However, there is little evidence that either was ever resident in Hamburg or that there existed a significant Christian community there. After Rimbert’s death, bishops of Bremen ceased to use the title of archbishops or mention Hamburg. For this reason, we omit Hamburg from Map IVA.
Map IVB: 910 C.E.
Note, however, that the bishops of Bremen soon revived their claim to archiepiscopal status (and resisted becoming suffragan to Cologne) on the basis of missionary efforts in Scandinavia which, if they ever bore fruit, would create new suffragan bishoprics. By c. 907, with papal permission, they were assigned the former archepiscopal title associated with Hamburg but remained resident in Bremen. To reflect this, on Map IVB and in subsequent maps, we situate the archbishopric in Bremen but label it as Hamburg-Bremen.
Map VA and VB
Map VA: 975 C.E.
By the middle of the tenth century, military expansion under the Ottonian successors to the Carolingians in East Francia made possible the establishment of a number of bishoprics in the vicinity of the Elbe and the region’s Slavic population, where Christianity was beginning to take root.
The first sees were established in the 940s at Havelberg and Brandenburg. Twenty years later, Otto I established several more, including an archbishopric at Madgeburg, to which all were made suffragan.
Note the establishment of the first bishopric among the Poles, at Poznań, around this same time (and perhaps, but not securely, subordinated to Magdeburg).
A see was also independently founded at Prague sometime in the mid-970s by the Přemyslid rulers of Bohemia; it became suffragan to Mainz.
Not shown here are the Danish sees of Aarhus, Ribe, and Hedeby (Schleswig), for which bishops were first named circa 948; nor Odense, probably established a few decades later. Except perhaps for a brief period after the conversion of the Danish King Harald Bluetooth to Christianity circa 965 and before the backlash under his successor, these were bishops in name only, not resident in their sees nor presiding over local Christian practice. All were subordinate to the archbishops of Hamburg-Bremen, who encouraged their foundation, it seems, so as to claim them as suffragans and retain their archiepiscopal status. The same holds for the see of Oldenburg/Starigard in nearby Slavic Wagria, ostensibly founded in 968, which, if it existed, did not survive the Slav rebellion of 983.
Map VB here reflects the destruction of sees beyond the Elbe as a consequence of the the Slav revolt against Ottonian lordship in 983.
Map VB: 990 C.E.
Map VI
Map VI: 1010 C.E.
Independent episcopal hierarchies were established among the Poles and the Magyars around the year 1000. (The see of Kołobrzeg, however, did not last much longer than a decade, as that region was dominated by the non-Christian Pomeranians.)
Many Hungarian sees are said to have been founded by St. Stephen and therefore before 1009, but most are poorly attested over the whole of the eleventh century. Rather than engaging the complicated historiography on the early years of these bishoprics, we omit them from all the maps here—leaving only the archbishopric of Esztergom as a placemarker.
In 1007, Henry II established a new see at Bamberg, where the bishop, exceptionally, was not made suffragan to any archbishop.
Map VII
Map VII: 1050 C.E.
Recent scholarship suggests that only around the year 1020/1022 were episcopal sees firmly established in Denmark—although missionary bishops without fixed sees had been active there previously and bishops in name only were occasional designated by the archbishops of Hamburg-Bremen. Exploiting their links to England and the archbishops of Canterbury, Danish kings thwarted the subordination of these new bishoprics to the archbishops of Hamburg-Bremen, in spite of the latters’ claims.
In 1028, the see of Zeitz was transferred to Naumburg, although bishops might be designated by either location. (We therefore label it “Zeitz-Naumburg” here, but situate it in Naumburg.
Map VIII
Map VIII: 1075 C.E.
In 1053, all Danish bishops were again made suffragan to the archbishops of Hamburg-Bremen, by papal decree. Soon thereafter, additional sees were founded at Schleswig; at Sigtuna, in Sweden; and, in 1068, in Norway at Oslo. It is likely that the Swedish see of Skara had been established by the mid-eleventh century as well, although some traditions put its foundation as early as 990. The Scandinavian sees are invariably poorly documented, however. It seems likely that, throughout the eleventh century, those bishops in residence were essentially either missionaries or royal chaplains—and no institutional development occurred around their ostensible cathedral churches. Scholars have also argued that, even at midcentury, the bishops assigned to Sweden were merely titular and non-resident—named, once again, only to enhance the status of Hamburg-Bremen as metropolitan.
From circa 1053 to 1066, the archbishop of Hamburg-Bremen assigned bishops to the Slav cities of Mecklenburg and Ratzeburg; however, because these were almost certainly non-resident, titular bishops we omit them from this map.
Around the same time a new bishopric was founded by the Přemyslids in Moravia, at Olomouc.
In 1072, an episcopal seat was established at Gurk in Carinthia. It was not only suffragan to Salzburg but proprietary (that is, the archbishop, not the crown, possessed the rights of appointment and investiture)—a unique situation, contested but reaffirmed throughout the twelfth century.
From the 1030s onward, political instability among the Poles meant that that many bishoprics had ceased to effectively function. They seem to have been gradually restored by 1075, when a new see was also added at Płock.
Map IX
Map IX: 1125 C.E.
Sometime in the later 1070s (perhaps), additional bishoprics were established in Norway, at Nidaros (today’s Trondheim) and Bergen. By 1125, a further see had been founded at Stavanger in Norway. The diocese at Linköping in Sweden may date as early as 1100.
Meanwhile, in 1103/4 Lund became an archbishopric with all the Scandinavian sees its suffragans—in the face of opposition from the archbishops of Hamburg-Bremen, who, but for a few years in the 1130s, were unsuccessful in reasserting their primacy.
Map X
Map X: 1155 C.E.
By the 1130s (and perhaps as early as 1125), two new Polish bishoprics had been established, at Lebus/Lubusz and for Cujavia (at Włocławek).
By 1140, the bishopric of Sigtuna had been moved to Uppsala, and a new see established at Västerås to govern the remainder of its diocese. Earlier, ca. 1129, another Swedish bishopric had been founded at Strängnäs.
Between 1140 and 1150, a number of bishoprics were established in the Slav lands east of the Elbe, as these regions came under German control. Those in the north were made suffragan to Hamburg-Bremen, while the revived sees of Havelberg and Brandenburg were subordinated to Magdeburg. Wollin, however, was independent of any metropolitan archbishop. Unusually, three of these sees (Havelburg, Brandenburg, and Ratzeburg), were assigned to the transnational order of canons regular known as the Premonstratensians.
In 1151, Nidaros was elevated to archiepiscopal status. Its suffragans included all the Norwegian sees, as well as other bishoprics of the North Sea (in Iceland, Greenland, the Orkneys, the Hebrides). Soon afterwards, an additional see was founded in Norway at Hamar.
Map XI
Map XI: 1175 C.E.
Many of the transelbian sees were established at sites of historic significance; later, several were transferred to locations of more contemporary relevance. Thus Oldenburg moved to Lübeck and Mecklenburg to Schwerin. By 1175 the see of Wollin was located in Cammin (Kamien Pomorski), after two decades at Grobe Abbey on the island of Usedom.
Moreover, in 1164 the see of Uppsala was elevated to an archbishopric, with all the Swedish bishops its suffragan. The diocese of Växjö, whose origins are obscure, may have been founded around this time.
Map XIIA
Map XIIA: 1190 C.E.
A missionary bishop, suffragan to Hamburg-Bremen, was established at Iršķile (Üxküll) in Livonia in 1186. In 1202, the see moved to Riga.
Map XIIB
Map XIIB: 1205 C.E.