Danevirke


 * For other uses of this and similar names, see Dannevirke (disambiguation).

The Danevirke (modern Danish spelling: Dannevirke; in Old Norse; Danavirki, in German; Danewerk) is a system of Danish fortifications in Schleswig-Holstein. This important linear defensive earthwork was constructed across the neck of the Cimbrian peninsula during Denmark's Viking Age. It was last used for military purposes in 1864.

The Danevirke stretches for 30km, from the marshes in the west of the peninsula to the town of Schleswig, which lies beside the Schlei (Danish: Slien) on the Baltic Sea coast, near the former Viking trade centre of Hedeby. Another wall, between the Schlei and the town of Eckernförde, defended the Schwansen peninsula.

According to written sources, work on the Danevirke was started by the Danish King Gudfred in 808. Fearing an invasion by the Franks, who had conquered heathen Frisia over the previous 100 years and Old Saxony in 772 to 804, Godfred began work on an enormous structure to defend his realm, separating the Jutland peninsula from the northern extent of the Frankish empire.

Carbon-14 dating however dates the initial construction to be in the second half of the 7th century, and Dendrochronology suggests that construction began not very long after 737 (a few decades before the reign of Gudfred).

New Carbon-14 dating in 2013 has revealed that the second stage started in the years around 500 AD, and the oldest fortification are even older than that.

Archaeological record
Archaeological excavations in 1969–75 established, with the help of dendrochronology, that the main structure of the Danevirke had been built in three phases between AD 737 and 968. It is, therefore, contemporary with Offa's Dyke, another great defensive structure of the late 8th century.

Recent investigations suggest that Danevirke was not only and not primarily built for military purposes. The archeologist Henning Hellmuth Andersen found that in an early stage the main "wall" consisted of a ditch between two low embankments. The historian argued that the Kograben (Danish: Kovirke) south of the main wall consists of an embankment accompanied by a ditch on its northern side, which would have been counterproductive for a Danish fortification. So the main wall, in its earliest stage, and the Kograben rather would have been shipping canals. The shortcut between Baltic Sea and North Sea via Schlei in the east and Treene and Eider in the west was understood previously, but historians believed that boats had been moved on rollers between the Schlei and Treene. See Portage.

An excavation in 2009–10 stonewall near Dannevirke Museum west of the town of Schleswig Dannevirke so far only port (Kalegat or Viglesport) was found, where Hærvejen crosses the rampart.

Size
The Danevirke is about 30 km long overall, with a height varying between 3.6 and 6 m. During the Middle Ages, the structure was reinforced with palisades and masonry walls, and was used by Danish kings as a gathering point for Danish military excursions, including a series of crusader raids against the Slavs of the south Baltic. In particular, the 12th-century King Valdemar the Great reinforced parts of the Danevirke with a brick wall, which enabled a continued military use of the strategically important structure. The reinforced parts of the structure are consequently known in Danish as Valdemarsmuren (Valdemar's wall).

Symbolism
During the prolonged nineteenth century political and military struggles between Danes and Germans over possession of the territory variously known as Sønderjylland or Slesvig by the Danes and Schleswig by the Germans, the Danevirke was used as a potent symbol of Danish nationalism. Specifically, it was a symbol of the Danish historical claim for the whole of this territory — although during the centuries since its construction the linguistic frontier has moved gradually northwards, so that in the 19th century the territory north as far as Flensburg as well as south of the Danevirke was predominantly German-speaking. The fiefdom remained as a Danish fief.

Second War of Schleswig
The last military use of the Danevirke was during the Second War of Schleswig in 1864. Due especially to the above-mentioned emotive nationalist symbolism, public opinion in Denmark had expected the coming battle to take place here, and the Danevirke was already under attack, although no battle took place there (except some early skirmishing near south of it), as the Danish Commander in Chief, General de Meza, withdrew to the trenches at Dybbøl due to threat of being outflanked, as the Schlei and the wetlands between the Danevirke and Husum had frozen solid in a hard winter; also, the territory immediately in front of the Danevirke had already fallen into German hands. This retreat came as a surprise to the Austro-Prussian army, and almost all of the Danish army succeeded in completing the evacuation. It resulted, however, in the abandonment of important pieces of heavy artillery, and it remains a matter of historical debate why the railway to Flensburg was never properly used for the evacuation. News of the retreat came as a great shock to Danish public opinion which had considered the Danevirke to be impregnable, and General de Meza was promptly relieved of his command.

The Danevirke has remained in German possession ever since.

Stages in the building of the Danevirke


Danevirke 1 — Hovedvolden ("the main rampart"), Nordvolden ("the north rampart"), Østervolden ("the east rampart") The first Danevirke was built in five stages, starting about 650, according to carbon-14 dating. The first three stages were simple ramparts of soil, and the fourth stage was a palisade rampart with heavy timber front, build in 737. In the final stages the timber palisade was reinforced with a heavy stone wall around the timber. Work said to have been started by Angantyr, and continued by Siegfried, and ended by Guðfrið according to annales in 808.
 * Hovedvolden: From Rejde Å (now called Rheider Au) to a small lake called Dannevirke Sø. It was the main segment of the Danevirke. About 2 m high and 12 m wide.
 * Nordvolden: From the northeastern side of Dannevirke Sø, and further north about 7 km.
 * Østervolden: About 3.3 km long, and protecting Schwansen.
 * A 900 m long submerged construction in Slien.

Danevirke 2 — Kovirke ("cow-work")/Kograben ("cow-moat" or "district moat") Built either by Guðfrið or by Harald Bluetooth (if it is the work mentioned as newly made in the Frankish royal annals in 808, then Harald did not build it) it stretched from the Rheide Å about 7 km to a southern extension of the Schlei bay which is now a lake called Selker Noor. Its palisade was about 3 m high, and was a little more solid than that on the first ramparts. The bank of earth behind the palisade was about 2 m high and 7 m wide. It had a V-shaped moat, 4 m wide and 3 m deep.

The construction period of this rampart should be some time between 770 and 970.

Danevirke 3 — Hovedvolden/Hauptwall/"main rampart", Krumvolden/Krummwall/"curved rampart", Buevolden/Bogenwall/"bow rampart"), Dobbeltvolden/Doppelwall/"double rampart", Forbindelsesvolden ("the connecting rampart")/Margarethenwall ("Margret's rampart") Hovedvolden was expanded, so that it was now about 5 m high and about 20 m wide. Krumvolden was built through the Rheide Å, and overlapped with Hovedvolden. Forbindelsesvolden closed a gap between Halvkredsvolden ("the semicircle rampart", a bank that protected Hedeby) and Hovedvolden near Dannevirke Sø. Buevolden and Dobbeltvolden protected an important road junction. This wall is connected to most of the building work is attributed to Harald Bluetooth. Arild Hvitfeldt's Danmarks Riges Krønike adds a little detail to the extension of the Danevirke in that time period. "Then summoned (Queen) Thyra (wife of Gorm the Old) Danes from all the kingdom's regions to meet at the border and under her supervision they built a wall of earth and timber from Slien over the moors to Trene. The men of Skåne received the western section from Karlegat to Trene. Zealanders and Funen dwellers received the section east from Slien (Schlei bay) to Karlegat. Jutlanders provided provisions to the whole army." This would place Thyra's extension sometime before 940. Forbindelsesvolden was attacked by Germans in 974.

Danevirke 4 — Hovedvolden/Hauptwall/"main rampart". Reinforcement on the Main Wall finished in 954, and a new Forbindelsevold build from 964 to 968. Harald Bluetooth is thought to be the main constructor.

Danevirke 5 — Forbindelsesvolden, Krumvolden, and Hovedvolden Under Canute IV of Denmark (1080–86) Denmark was at war with the German empire. The Danevirke was strengthened at the beginning of the 12th century: the moats were deepened and the ramparts were made higher. A granite boulder palisade wall was built on a part of Hovedvolden.

Danevirke 6 — Hovedvolden and Thyraborg Valdemar I fortified the rest of Hovedvolden with the famous "Valdemar-wall", a 7-m high wall of stones in mortar on a granite boulder base, propped up with buttresses and covered with tiles. This was a large reinforcement, and doubtless deterred many who tried to send an army northwards through Jutland. It was the last true reinforcement of the ramparts. Later Thyraborg castle was built.

The Danevirke began to lose its purpose in the 14th century, owing both to the expense of manning it and to the development of ballistas, trebuchets, and similar siege engines.

The Danevirke in World War II
Following the Allied invasion of Normandy during World War II, the Wehrmacht feared that a second Allied invasion might take place through Denmark, and contemplated converting the earthen wall into an anti-tank trench to counter this threat. Had the proposal been implemented, it would have destroyed the structure.

Hearing of the plans, Danish archaeologist Søren Telling — aware that all archaeological investigation was under the ultimate jurisdiction of SS chief Heinrich Himmler — immediately telephoned both the head of the SS's archaeological department, Amt für Ahnenerbe ("Office for ancestral heritage"), and Himmler himself. Telling argued strongly against the destruction of an important remnant of "Aryan civilization" and Himmler authorized him to stop the construction of the anti-tank trench. He informed Telling that a written order would be dispatched but that it would take several days to arrive. Telling then drove to the site and ordered the commanding Wehrmacht officers to immediately stop the construction process. When the local Wehrmacht commander refused, Telling threatened him with reprisals from the SS. Construction was called off and Himmler's written order arrived two days later countering the Wehrmacht's original instructions. Telling later settled near the site and considered himself a custodian of it until his death in 1968.

The Danevirke in popular culture
As a symbol of Danish autonomy from Germany, Dannevirke was adopted as the title of several Danish journals during the nineteenth century. The most notable of these was published by N. F. S. Grundtvig from 1816–19.

The town of Dannevirke in New Zealand was founded by Danish, Norwegian and Swedish settlers in 1872, when the Danevirke's loss to the Germans was a recent and very painful memory.

Literature

 * H. Hellmuth Andersen: "Til hele rigets værn, Danevirkes arkæologi," edited by Moesgård und Wormianum in 2004 (in Danish)