Hedeby (, Old Norse Heiðabýr, German Haithabu) was an important trading settlement in the Danish-northern German borderland during the Viking Age. It flourished from the 8th to the 11th centuries.
The site is located towards the southern end of the Jutland Peninsula. It developed as a trading centre at the head of a narrow, navigable inlet known as the Schlei, which connects to the Baltic Sea. The location was favorable because there is a short portage of less than 15 km to the Treene River, which flows into the Eider with its North Sea estuary, making it a convenient place where goods and ships could be ported overland for an almost uninterrupted seaway between the Baltic and the North Sea and avoid a dangerous circumnavigation of Jutland.
Hedeby was the largest Nordic city during the Viking Age and used to be the oldest city in Denmark until the site became part of Germany.
The city of Schleswig was later founded on the other side of the Schlei, and gave the duchy its name. Old records mention two bridges connecting the two towns. Hedeby was abandoned after its destruction in 1066.
The site of Hedeby is located in the Duchy of Schleswig, which was traditionally the personal territory of the kings of Denmark. But the Kingdom of Denmark lost the area to Austria and Prussia in 1864 in the Second Schleswig War, and it is now in Germany. Haddeby is now by far the most important archaeological site in Schleswig-Holstein. The Haithabu Museum was opened next to the site in 1985.
Read more about Hedeby: Naming