Short answers, pulled from the story.
Hedeby was located near the southern end of the Jutland Peninsula, in what is now the Schleswig-Flensburg district of Schleswig-Holstein, Germany. Its position between the Frankish Empire and the Danish Kingdom placed it on both the north-south trade route connecting Franks and Scandinavians and the east-west corridor linking the Baltic Sea to the North Sea, making it the second largest Nordic town of the Viking Age after Uppåkra.
Hedeby was destroyed twice in quick succession. King Harald Hardrada of Norway burned it in 1050 by sending flaming ships into the harbour. West Slavic forces completed the final destruction in 1066. After the second sacking, the population relocated across the Schlei inlet to Schleswig, and Hedeby was gradually submerged by rising water levels until its location was forgotten.
Al-Tartushi, a late 10th-century traveller from Cordoba in Spain, described Hedeby as a very large town at the extreme end of the world ocean. He recorded that the inhabitants worshipped Sirius, that fish was the main food, that women held the right to divorce, and that both men and women wore artificial eye make-up. He was unimpressed by the local singing, comparing it to sounds more bestial than a dog.
Hedeby produced textiles ranging from coarse sailcloth to fine worsted wool, as well as combs, leather goods, ironwork, and goldsmith products. More than 7,700 decorative beads made from materials including carnelian, amber, mosaic glass, and silver were found at the site. The town also participated in the Viking slave trade, exchanging captives and furs for Arab silver dirham and silk along the Volga trade route to the Abbasid Caliphate.
Hedeby and the nearby Danevirke earthworks were inscribed on the UNESCO World Heritage List in 2018. They were recognised together because of Hedeby's historical importance during the Viking Age and the exceptional preservation of both the settlement remains and the defensive earthworks.
Sophus Muller rediscovered the exact location of Hedeby in 1897. Small-scale excavations began in 1900 under Johanna Mestorf. Despite more than a century of work, only 5% of the settlement and 1% of the harbour have been fully investigated. The Hedeby Viking Museum opened next to the site in 1985, and in 2005 an archaeological reconstruction program placed copies of original Viking houses on the site.