The Danevirke (‘work of the Danes’), a 30-kilometre (19-mile) wall which runs across the entire state of Schleswig-Holstein in northern Germany, is considered the largest earthwork in northern Europe. A team of archaeologists led by Astrid Tummuscheit from the state archaeology office of Schleswig-Holstein has recently studied a three-metre thick part of the wall from the eighth century near Hedeby (also known as Haithabu in German). At a press conference on Friday August 27^th, Tummuscheit’s team announced the discovery of what they have described as a ‘sensation’ - a five-metre wide portal and the only gate leading through the Danevirke.

According to written sources from the time, the gate was called 'Wiglesdor' and was situated next to a customs station and an inn that included a bordello. Although experts knew the approximate location of the gate, archaeologists were not allowed to carry out excavation work because it was on the site of a café. However, when Café Truberg went bust in 2008, the energy company E.on paid for the café to be demolished and archaeologists began to excavate the site.

The Danevirke is notably mentioned in the Frankish chronicles of Einhard who was in the service of Charlemagne. Einhard records that the Danish king Godfred strengthened the Danevirke at the beginning of the ninth century. However, the latest studies suggest that the earliest parts of the wall may have been built earlier. The foundation stone may have been laid as early as the seventh century by the Frisians and not by the Danes.

But why did the Frisians, traditionally viewed as invaders and plunderers, construct this defensive fortification? Hedeby developed in the eighth century as an important trading centre on one of the main Viking trading routes from the east to the west. Goods would arrive at Hedeby, situated at the head of the Schlei Inlet, from the Baltic Sea and would then have to be transported 18 kilometres overland to the Treene River. They would then be reloaded onto boats and sailed into the North Sea. However, whilst being transported overland goods were open to attack and it is believed that the Danevirke was built to protect this trade artery connecting eastern trade routes with those to the west.

Archaeologists are now planning to excavate the gate down to the old street level in the hope of discovering paving stones or hinges.

Matthias Schulz reports in Der Spiegel.

There are also images of the Danevirke and of recent excavation work on the website of Der Spiegel.