Slavic bridges in northeastern Germany and their cultural background

Abstract

The research on the Slavic occupation in northeastern Germany of the 8^th-12^th century focused primarily on defensive features – the hillforts and settlements present in the area between the Lower Oder in the east and the Middle Elbe in the west, as well as in the eastern part of the state of Schleswig-Holstein, all the way to Limes Saxoniae. It stretched from the middle course of the Elbe near Lüneburg, where a small river the Delvenau flows into it and further north, to the shores of Lake Stecknitz and the course of the Trave River in the vicinity of Alt-Lübeck. Further north, Limes reached the Schwentine River, running in a deep valley all the way down to the final section of that river, which flows into the Baltic in the north, into the Kiel Fjord. The mentioned Limes did not serve as any linear and fortified border, unlike the Roman limes, but merely a wide belt of natural barriers in the form of rivers, deep valleys, backwaters and wetlands, as well as vast forest complexes. It was created by the order of Charlemagne in the early 9^th century, as a border between the empire of Franconia and the Slavic tribes residing to the east of the Limes – the Obotrites, the Wagrians, and the Polabians, as a defence against their aggression. 

The discussed area of the northeastern Germany, inhabited by the Slavs, encompasses the state of Mecklenburg-Vorpommern, the eastern part of the state of Schleswig-Holstein, all the way to the mentioned Limes Saxoniae and a small northern part of the state of Brandenburg, which constitutes the smallest fragment of the area covered by the catalogue of hillforts and settlements with bridge relics. In this area, about 250 Slavic hillforts have been recorded so far, dating back from the 8^th to the 12^th century.  

The area of the northeastern part of Germany, in the interfluvial zone between the lower Oder and the middle Elbe, is characterised by glacial landscape of the most recent Baltic glaciation, with hills and moraine uplands, outwash plains, and numerous glacial throughs with rivers and lakes. Considering the character of the inhabited lake islands and peninsulas that is defensive, not only due to the nature of the environment, one should bear in mind that in the old forest landscape repeatedly described by contemporaneous chroniclers that used to prevail in the area in question, lakes and rivers provided the most suitable conditions for the movement of people and for transporting goods. The bodies of water provided also many advantages essential for sustaining the daily life of their inhabitants, such as fishing and waterfowl hunting.   

All the features that we are interested in were closely linked to the contemporaneous river system, with settlements established mainly on the numerous lake islands and peninsulas, and suitable locations on the shores and banks of these reservoirs and rivers. As for communications routes, aside from those where boats and rafts were utilised, the most convenient ones were bridge crossings and fords, whereas in irrigated, meadowy and marshy areas of the lacustrine and river valleys, bridge-like boardwalk structures with wooden decks were in use.

It is worth mentioning that northeastern Germany features approximately 1,400 lakes covering over 1 ha each, where about 230–250 islands can be found along with several tens of thousands of kilometres of waterways in the form of small and medium-sized rivers, formerly highly meandering and largely already canalized in the modern era, as well as two bigger rivers – the Oder and the Elbe. These lakes hold numerous islands and peninsulas occupied by the Slavs and also riverbanks of some rivers. Many of them used to be linked to the opposite shore by means of bridge crossings.

 All the features, both those whose location has been confirmed and those alleged, known so far predominantly from northeastern Germany, were largely found as early as in the 19^th century and in the first half of the subsequent century. These discoveries were made accidentally, mainly in the course of waterway civil works consisting in delineating new, possibly straight water transport routes for the developing river transport.

Some structural elements of bridge crossings were unearthed also in the course of peat excavation works, in depressions left after former shallow kettle lakes. Many of them were discovered also accidentally during reclamation and draining of shallow lakes to acquire new lands for farming and horticulture, as well as for setting up new meadows for cattle grazing. Every now and then, piers of the bridge load-bearing structures would get pulled out from the unearthed depressions of former lakes with complete unawareness of their historical value and then used as inexpensive firewood. Back then, these works yielded only scarce information about these discoveries without any broader context pertaining to the original access functions and without any interpretation made regarding the framework of this former hydraulic structure. 

Nonetheless, it was not until many decades later that subsequent archaeological works were undertaken, since the first research on the hillforts with bridge crossings was not conducted until the post-war years, in partially drained lakes, i.a., in Teterow (1950–1953) and Fergitz (1962–1965). In the case of features initially located in the lacustrine parts close to the lake islands, it was necessary for archaeologists to carry out direct underwater prospecting in this environment that was a novelty to them. Hence, expanding the knowledge about the location and the course of these structures, as well as reconstructing the previously little-known Slavic bridges in a more comprehensive manner was not possible in archaeology until the most recent decades. This is related to the formation of specialist underwater archaeological groups in northern Germany, i.a., at Kiel University and the University of Greifswald, established to address the research on west-Slavic bridges, among others. These studies confirmed that the post-frame structures unearthed at the bottom of the lakes, deposited in the bottom of the mentioned lakes either vertically and diagonally, are remains of load-bearing structures of bridges. The post-frame structures aside, remnants of their surface structures lying at the bottom of the lakes were also encountered, specifically, cap beams that connect individual piers or multi-column piers over the water surface, and horizontal beams reinforcing the deck and the dranice [manually split wooden tiles – Translator’s note] lying on top of them forming the bridge deck. The mentioned bridge relics were deposited at the bottoms of reservoirs as a result of construction disasters, natural disasters – fires, drifting ice and floods, or due to military activities.

Often, we find mentions of military actions on the bridges in medieval chronicles. Over a course of several centuries, the areas inhabited by Slavic tribes were repeatedly attacked by the troops of Franconian, German, Danish and Polish rulers that as part of military campaigns often had to move along supra-regional land roadways and bridges leading directly to the besieged and captured hillforts and settlements. We find accounts of many acts of armed aggression recorded as part of tribal fights between Slavic dukes.

In recent decades, much success in systematic underwater research of bridge crossings has been made owing to the application of dendrochronological analyses that has not only facilitated dating results for the years in which the bridges were created but also allowed for the recreation of the dates of their necessary remodelling, repairs, and the raising of other structures of this sort in that location. Based on this information, we know that wooden bridges were not construction investments of significant durability. As yet, of the approximately 700 hillforts situated over the vast territory of the northwestern Slavs between the Elbe and the Vistula, dendrochronological results have been obtained for only a small percentage, ca. 3%. Based on the previous data pertaining to the situation of the bridges, we know also that new structures were always built either at the same location or immediately next to the previous feature using the course of old accessways. Such developments are known to us from studies on at least several bridge crossings. 

This is because the layout for the construction of the bridges in the very same location was necessitated by users of communications routes and the bridges heading to hillforts – oftentimes ducal seats – on a daily basis, such as advisors and administrative messengers, merchants, food suppliers, craftsmen, and makers of all goods essential for hillforts to operate. In many island-situated hillforts, temples and sanctuaries (chramy) were in use for a long time, serving as venues for performing ceremonial rites and rituals for tribal gods.

Such is the current state of our knowledge on bridge crossings in northeastern Germany, from the Oder in the east all the way to Limes Saxoniae in the west, which runs in the eastern part of the state of Schleswig-Holstein. In that area, nearly 80 bridge features have been recorded, including only ca. 40 whose location is certain, functionally connected with the island hillforts and settlements.

A similar number is represented by alleged bridge features that have not been confirmed as yet in the course of underwater prospecting and whose location has not been specified. One must include to this category of bridges also the considerably high amount of information contained in medieval written sources, on the margins next to accounts referring to battles on hillfort bridges or the granting of fiefs where bridges occasionally considered topographic elements of these documents. One should not fail to list vast amounts of information pertaining to the inhabitants of settlements in lake shore and riverbank areas and professional fishermen whose nets would get damaged by underwater palowiska (palings), that is, pier-supported structures of bridges driven into the bottom of rivers and lakes.

Considering the above, this catalogue of Slavic bridges in northeastern Germany includes solely features whose access function has been confirmed and whose location has been specified in the past and present waterway network, 39 features in total. In a few cases, this also included features showing a high probability of serving as bridge crossings in the past, all of them waiting to be further examined, excavated and properly functionally interpreted. The hillforts and settlements with bridges have been included in the bridge catalogue according to the following pattern: village/town and state name, their jurisdiction, and site number.  Further specifications for the catalogue entries include site type, geographical location of the site, research, followed by information on the remnant bridge(s), chronology (based on archaeological determinants and dendrochronological analysis results); the catalogue end with references and remarks.