The Nordic Bronze Age, which occurs in Scandinavia between 1700 BCE and 600 BCE, is characterized by a warm climate that had begun with a climate change circa 2700 BCE (comparable to that of present-day Mediterranean).

The warm climate permits a relatively dense population and good farming: for example, grapes are grown in Scandinavia at this time.

Evidence developed by archaeologists and linguists suggests that a people or group of peoples sharing a common material culture dwell in a region defined by the Nordic Bronze Age culture, centered in Schleswig, and extending throughout Scandinavia.

Succeeding the Corded Ware culture, the Nordic Bronze Age it is generally considered the direct predecessor and origin of the Proto-Germanic culture of the Pre-Roman Iron Age.

Its language is referred to as Proto-Germanic.

Even though Scandinavians joined the European Bronze Age cultures fairly late through trade, Scandinavian sites present rich and well-preserved objects made of wool, wood and imported Central European bronze and gold.

The Scandinavians adopted many important European and Mediterranean symbols while adapting these to create a unique Nordic style.

Mycenaean Greece, the Villanovan culture, Phoenicia and Ancient Egypt have all been identified as possible sources of influence for Scandinavian artwork from this period.

The foreign influence is believed to have been due to the amber trade.

Amber found in Mycenaean graves from this period originates from the Baltic Sea, so it is reasonable to assume that the culture that arose in the Nordic Bronze Age constituted one supply end of the so-called Amber Road.

Many petroglyphs depict ships, and the large stone formations known as stone ships suggest that shipping played an important role.

Several petroglyphs depict ships that have been identified as plausibly Mediterranean.

The oldest parts of the defensive works of Danevirke near Hedeby at least date from the summer of 755 and will be expanded with large works in the tenth century.

The size and number of troops needed to man it indicates a quite powerful ruler in the area, which might be consistent with the kings of the Frankish sources.

In 815, Emperor Louis the Pious attacks Jutland apparently in support of a contender to the throne, perhaps Harald Klak, but is turned back by the sons of Gudfred, who most likely are the sons of the above-mentioned Gudfred.

At the same time St. Ansgar travels to Hedeby and starts the Catholic Christianization of Scandinavia.

Hedeby is first mentioned in the Frankish chronicles of Einhard (804) who was in the service of Charlemagne, but was probably founded around 770.

The Danish king Godfred (Latin: Godofredus) in 808 destroys a competing Slav trade center named Reric, and it is recorded in the Frankish chronicles that he moved the merchants from there to Hedeby.

This may have provided the initial impetus for the town to develop.

The same sources record that Godfred strengthened the Danevirke, an earthen wall that stretched across the south of the Jutland peninsula.

The Danevirke joined the defensive walls of Hedeby to form an east-west barrier across the peninsula, from the marshes in the west to the Schlei inlet leading into the Baltic in the east.

The town itself is surrounded by earthworks on its three landward sides (north, west, and south).

Henry I and his Christian forces defeat a pagan Danish army under King Gnupa and conquer Hedeby.

Gnupa is mentioned on the two Sigtrygg Runestones raised near Schleswig by his wife Asfrid for their son Sigtrygg.

Likewise, a Danish king Chnuba is named by Widukind of Corvey's Saxon chronicles as having been defeated and forced to accept baptism in 934, and Olav Tryggvasson's Saga tells of Gnupa's defeat by Gorm the Old.

However, this chronology would contradict that of Adam of Bremen, who places the succession and subsequent defeat of Sigtrygg during the tenure, from 909 to 915 or 917, of Archbishop Hoger of Bremen.

The late and legend-influenced Gesta Danorum of Saxo Grammaticus names a nobleman Ennignup serving as guardian for a young king Knut at some time prior to king Gorm the Old and it has been suggested he may be a confused representation of Gnupa.

The background for the creation of the newly palisaded town of Hedeby had been to protect the interests of trade.

Without peace and security merchants will stay away.

It is up to the king to enforce market peace and take steps to do whatever possible to keep buccaneers from raiding the ships bringing goods to the market.

In return for this protection he can collect dues from the merchants.

Ibrahim ibn Yaqub al-Tartushi, a traveler from Cordoba, provides one of the most colorful and often quoted descriptions of life in Hedeby, which may be a significant hub by Scandinavian standards, but lacks the wealth and comfort of al-Andalus.

Al-Tartushi is unimpressed: "Slesvig (Hedeby) is a very large town at the extreme end of the world ocean....

The inhabitants worship Sirius, except for a minority of Christians who have a church of their own there....

He who slaughters a sacrificial animal puts up poles at the door to his courtyard and impales the animal on them, be it a piece of cattle, a ram, billygoat or a pig so that his neighbors will be aware that he is making a sacrifice in honor of his god.

The town is poor in goods and riches.

People eat mainly fish which exist in abundance.

Babies are thrown into the sea for reasons of economy.

The right to divorce belongs to the women....

Artificial eye make-up is another peculiarity; when they wear it their beauty never disappears, indeed it is enhanced in both men and women.

Further: Never did I hear singing fouler than that of these people, it is a rumbling emanating from their throats, similar to that of a dog but even more bestial."

The flow of Islamic silver through Russia to Scandinavia had dried up at the exhaustion of the Muslim’s world’s silver mines in about 965, prompting the Scandinavians to seek new sources of silver—the main fuel of the Scandinavian economy for the last century—through raiding in the west.

Hedeby, the largest Nordic city during the Viking Age and the oldest city in Denmark, had developed as a trading center at the head of a narrow, navigable inlet known today as the Schlei which connects to the Baltic Sea. With no silver to coin, the mint at Hedeby had sonn ceased operations.

The location of Hedeby is favored because there is a short portage of less than fifteen kilometers to the Treene River which flows into the Eider with its North Sea estuary, making a convenient place where goods and Viking ships can be ported overland for an almost uninterrupted seaway between the Baltic and the North Sea and avoiding a dangerous circumnavigation.

The Saxons in 974 take Hedeby from the Danes.

Harald Bluetooth, king of Denmark from 935, is the first Danish monarch to become a Christian.

He ends the Saxons’ seven-year occupation of Hedeby in 983.

Harald Hardrada, now sole king of Norway, also wants to reestablish Magnus's rule over Denmark, and in the long term probably seeks to restore Cnut the Great's North Sea Empire in its entirety.

While his first proposal to invade Denmark had fallen through, the next year Harald had embarked on what will turn into constant warfare against Sweyn II of Denmark, from 1048 almost yearly until 1064.

Similar to his campaigns (then together with Sweyn) against Magnus's rule in Denmark, most of his campaigns against Sweyn consist of swift and violent raids on the Danish coasts.

He had plundered Jutland in 1048, and in 1049 he pillages and burns Hedeby, at this time the most important Danish trade center, and one of the best protected and most populous Scandinavia towns, by sending several burning ships into the harbor.

Hedeby as a civil town will never recover from Harald's destruction, and will be left completely desolate after Slavic tribes loot what remains in 1066.

One of two conventional battles is set to be fought between the two kings later the same year, but according to Saxo Grammaticus, Sweyn's smaller army was so frightened when approached by the Norwegians that they chose to jump in the water trying to escape; most drowned.

Harald is victorious in most of the engagements, but he will never succeed in occupying Denmark.

Slavs sack and burn Hedeby in 1066, after which the town will be slowly abandoned.