Carolina fossa

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Remains of the Carolina fossa in Graben near Treuchtlingen
The various projects to connect the Main and Danube

The Fossa Carolina (also called the Karlsgraben ) was a connection between the Swabian Rezat and Altmühl in Bavaria .

purpose

During the Carolingian era in the 790s, the building was intended to create a connection between the river system of the Rhine and the Danube . In this respect, the Karlsgraben is a forerunner of the Ludwig-Danube-Main Canal and the Main-Danube Canal . The aim of the company was to improve the traffic situation for the traders, who first traveled with their ships from the Rhine towards the Danube via the Main to Weißenburg on the Swabian Rezat, where the convenient trade route ended shortly before the main European watershed. He overcame the European watershed southwest of Dettenheim at an altitude of 419  m above sea level. NN . The canal was located not far from the Treuchtlingen district of Graben in the central Franconian district of Weißenburg-Gunzenhausen . The canal made it possible for traders from the two adjacent river systems to enter the other by ship, thus expanding their range of activities. The argument often found in the literature that the canal was built for military reasons to bring Karl's navy from the Danube back into the Rhine was no longer tenable. Strategic motives were not decisive, especially since the king and later emperor Karl had enough ships for military operations in both river systems. With new research and especially dating, strategic reasons are being discussed again.

history

Construction of the Karlsgraben, artist's representation in the Würzburg bishop's chronicle of Lorenz Fries.
Remnants of the Carolina fossa north of Graben

According to previous knowledge, the preparatory work for the construction of the Karlsgraben began in 792 under uncertain political circumstances, which were marked by conflicts with Pippin the Hunchback and Duke Tassilo .

In 793 Charlemagne had an approximately three-kilometer-long canal excavated near today's place Graben near Treuchtlingen , which established the connection between the Sualafeldgau and the Nordgau .

Statements by chroniclers that unfortunate soil and weather conditions led to the project being abandoned are now viewed as inaccurate, as the majority of contemporary sources report that the sewer was ready and usable. The fact that it was hardly used and was abandoned soon after its construction was probably due to the great effort that the canal passage required and the tolls that were supposed to amortize the construction. Obviously, the efforts were not worth it for the dealers in their day-to-day business.

However, there are other hypotheses that the canal was in use for a longer period of time.

A significantly earlier classification of the Karlsgraben is obsolete, which as an employment measure for the nearby Roman garrison in Fort Biriciana near Weissenburg (90-253 AD) would also have created a navigable connection to other troops on the Lower Rhine . Against this thesis speaks in particular that the shipping route created by the ditch would have been partly on non-Roman territory.

The early canals passed through to the development of the chamber sluice of a series of dam limited water attitudes. In between, the differences in level were overcome on slides or rollers. A reservoir was built near the Karlsgraben to supply water to the apex level. An early medieval dam recently discovered on the Altmühl near Treuchtlingen was initially interpreted as a dam for the water supply of the canal, until a C-14 dating indicated its lower, high medieval age. Furthermore, it could be proven that the river bed of the young Rezat was relocated to supply the northern section of the canal with water. After all, the Karlsgraben was quite suitable for the inland waterways common at the time.

Today an approximately 500 meter long water surface and adjoining up to 10 meter high earth walls made of excavated material have been preserved from the Fossa Carolina.

protection

Remnants of the Carolina fossa northeast of Graben
Remnants of the Carolina fossa northeast of Graben

The Fossa Carolina is designated by the Bavarian State Office for the Environment as geotope 577G003 (see the list of geotopes in the Weißenburg-Gunzenhausen district ). At the same time, the Fossa Carolina was included in the list of the most beautiful geotopes in Bavaria . The Fossa is a registered natural monument .

The building is registered under the monument number D-5-77-173-84 as an architectural monument by the Bavarian State Office for the Preservation of Monuments in the Bavarian Monument List. The underground and surface components are registered as ground monuments under monument numbers D-5-7031-0168 and D-5-7031-0181. The Fossa Carolina belongs to the protected building ensemble Fossa Carolina with the town center Graben .

Archaeological excavations

In autumn 2012 an investigation of the remains of the monument began as part of an interdisciplinary project of the German Research Foundation by scientists from the universities of Jena and Leipzig and the Bavarian State Office for Monument Preservation . According to the Jena archaeologist Lukas Werther, the Karlsgraben, at least three kilometers long, had a navigable width of five to six meters and was probably 70 centimeters deep. According to Werther, tens of thousands of oak planks were rammed into the ground for the bank reinforcement. The scientific dating of the excavated oak planks using dendrochronology showed with great certainty that the oaks were felled in the years 792 and 793 AD. The late wood of the year 793, which has not yet developed or is incompletely developed, indicates a felling period between summer 792 and autumn 793. The autumn of 793 is given in both the Reichsannalen and the Einhardsannalen as the construction time of the canal when Charlemagne was present at the construction site.

Extensive archaeological and geoarchaeological investigations were carried out near Dettenheim for these investigations from October 2014 to the end of July 2015. In addition to extensive rescue excavations, which had to take place due to the construction of a bypass road for Dettenheim, a project by the German Research Foundation (DFG) was about the proof of a theory that assumed a Carolingian foundation in the road embankment from Dettenheim to Treuchtlingen, about water here to dam for the Karlsgraben and deliver it there via the Swabian Rezat. The theory turned out to be obsolete.

Further research excavations on the trench itself took place in summer 2016.

Researchers from the universities of Jena, Leipzig and Kiel compared the historical course of the canal with the ideal line that a modern engineer would choose based on geological data. The route determined is strikingly consistent with the historical one. The lines even cross directly at the watershed. The researchers found no traces of a navigable canal west of Graben between the visible remains of the historic canal and the Altmühl.

Special exhibition

The results of the research project so far were presented in 2014 in a special exhibition in Mainz at the Museum of Ancient Shipping of the Roman-Germanic Central Museum and in Munich . Another exhibition that was not originally planned took place in Treuchtlingen because of the great interest on site. In the volume accompanying the exhibition Großbaustelle 793 - The Charlemagne canal project between the Rhine and the Danube , the participating scientists reported on the latest findings in over 25 articles.

See also

literature

  • Christoph Zielhofer, Lukas Werther, Peter Dietrich, Stefanie Berg-Hobohm, Peter Ettel: The Canal of Charlemagne. An early medieval project with a European dimension. In: Geographische Rundschau - September issue 9/2017, pp. 12-18.
  • Eva Leitholdt, Christoph Zielhofer u. a .: Fossa Carolina: The First Attempt to Bridge the Central European Watershed - A Review, New Findings, and Geoarchaeological Challenges. In: Geoarchaeology 27 (2012), pp. 88-104.
  • P. Ettel: The Main as a communication and trade route in the early Middle Ages - Fossa Carolina, castles, royal courts and the supraregional Karlburg trading center. In: Rivers as communication and trade routes. Rivers as communication and trade routes. Marschenratskolloquium 2009. Settlement and coastal research in the southern North Sea area 34, Rahden / Westphalia 2011, pp. 201–226.
  • Stefanie Berg-Hobohm , Britta Kopecky-Herrmanns: Scientific investigations in the area of ​​the Karlsgraben (Fossa Carolina). In: Reports of the Bavarian Land Monument Preservation. No. 52 (2012), pp. 403-418.
  • Gotthard Kießling: Weissenburg-Gunzenhausen district (= Bavarian State Office for Monument Preservation [Hrsg.]: Monuments in Bavaria . Volume V.70 / 1 ). Karl M. Lipp Verlag, Munich 2000, ISBN 3-87490-581-0 .

Web links

Commons : Fossa Carolina  - Collection of Images, Videos, and Audio Files

Individual evidence

  1. ↑ Location on the historical map at BayernAtlas Klassik
  2. ^ Grand failure: The "Karlsgraben" between the Rhine and the Danube , Neue Zürcher Zeitung , July 24, 2014.
  3. ↑ a b Ralf Molkenthin: Streets of water. Technical, economic and military aspects of inland navigation in Central Europe in the early and high Middle Ages . LIT Verlag, Münster 2006, ISBN 3-8258-9003-1 , p. 54-81 .
  4. ↑ a b c d press report at nordbayern.de from July 4, 2017 (with pictures of the excavations)
  5. ↑ M. Eckoldt (Ed.): Rivers and canals. The history of the German waterways. DSV-Verlag, 1998, pp. 451-457.
  6. ^ Konrad Spindler: The canal construction of Charlemagne. His reflection in the medieval sources and the current state of archaeological research . In: Konrad Spindler (ed.): Man and nature in medieval Europe. Archaeological, historical and scientific findings . Wieser Verlag, Klagenfurt 1998, ISBN 3-85129-268-5 , p. 47-100 .
  7. ↑ Eva Leitholdt, and Christoph Zielhofer. a .: Fossa Carolina: The First Attempt to Bridge the Central European Watershed - A Review, New Findings, and Geoarchaeological Challenges. In: Geoarchaeology 27 (2012), pp. 88-104.
  8. ↑ Stefanie Berg-Hobohm , Britta Kopecky-Herrmanns: Scientific investigations in the area of ​​the Karlsgraben (Fossa Carolina). In: Reports of the Bavarian Land Monument Preservation. No. 52 (2012), pp. 403-418.
  9. ^ Robert Koch: Fossa Carolina. New insights into the shipping canal of Charlemagne . In: Konrad Elmshäuser (Ed.): Ports, Ships, Waterways. To the shipping of the Middle Ages . Bremerhaven 2002, ISBN 3-934613-37-3 , p. 54-70 .
  10. ↑ Geotop: Karlsgraben (accessed on September 1, 2013; PDF; 149 kB)
  11. ↑ Bavaria's most beautiful geotopes , Bavarian State Office for the Environment , accessed on July 20, 2015.
  12. ↑ a b List of monuments in Treuchtlingen in the Bavarian State Office for Monument Preservation
  13. ^ Horst M. Auer: Karlsgraben consisted of a chain of ponds. Nürnberger Nachrichten, August 28, 2014.
  14. ↑ Peter Ettel, Falko Daim, Stefanie Berg-Hobohm, Lukas Werther, Christoph Zielhofer (eds.): Large construction site 793 - Charlemagne's canal project between the Rhine and the Danube. Verlag des Römisch-Germanisches Zentralmuseums, Mainz 2014, ISBN 978-3-88467-232-7 , p. 42.
  15. ↑ Jan Stephan: An important Iron Age settlement discovered in Dettenheim , www.nordbayern.de, May 24, 2015, accessed on August 3, 2017 ; Werner Somplatzki: Sensational finds during excavations , Altmühlbote, September 11, 2015, accessed on August 3, 2017
  16. ↑ Stefanie Berg-Hobohm, Britta Kopecky-Hermanns, Hans von Suchodoletz: Conceptual geoarchaeological work as a link between planning, excavation and scientific research - the Dettenheim colluvia .
  17. ↑ Patrick Shaw: Riddle Karlsgraben: Franks were the first. Nürnberger Nachrichten, August 21, 2019.
  18. ↑ Major construction site 793: Charlemagne's canal project between the Rhine and the Danube , Römisch-Germanisches Zentralmuseum , accessed on July 20, 2015.
  19. ↑ Peter Ettel, Falko Daim, Stefanie Berg-Hobohm, Lukas Werther, Christoph Zielhofer (eds.): Large construction site 793 - Charlemagne's canal project between the Rhine and the Danube. Verlag des Römisch-Germanisches Zentralmuseums, Mainz 2014, ISBN 978-3-88467-232-7 , accompanying volume for the exhibition of the same name

Coordinates: 48 ° 59 ′ 2 ″  N , 10 ° 55 ′ 18 ″  E