Birka was founded around AD 750 by either a king in order to control and expand trade or it emerged from a seasonal trading place around.
It is one of the earliest urban settlements in Scandinavia.
Birka was the Baltic link in the river and portage route through Ladoga (Aldeigja) and Novgorod (Holmsgard) to the Byzantine Empire and the Abbasid Califate.
Birka was also important as the site of the first known Christian congregation in Sweden, founded in 831 by Saint Ansgar.

As a trading center Birka most likely offered furs and iron goods as well as craft products, in exchange for various materials from much of Europe and western Asia.
Furs were obtained from the Sami, Finns, and people in northwestern Russia as well as from local trappers.
Furs included bear, fox, marten, otter, beaver and other species.
Reindeer antler was an important item in exchange as well as hand-carved combs made from antler.
Also walrus teeth, amber, and honey were exchanged.

Foreign goods found from the graves of Birka include glass and metal ware, pottery from the Rhineland, clothing and textiles including Chinese silk, Byzantine embroidery with extremely fine gold thread, brocades with gold passementerie and plaited cords of high quality.
From the ninth century onwards coins minted at Haithabu in northern Germany and elsewhere in Scandinavia start to appear.
The vast majority of the coins found at Birka are however silver dirhams from the Caliphate.
English and Carolingian coins are rare.

Sources of Birka are mainly archaeological remains.
No texts survive from this area, though the written text Vita Ansgari ("The life of Ansgar") by Rimbert (c. 865) describes the missionary work of Ansgar around 830 at Birka, and Gesta Hammaburgensis Ecclesiae Pontificum (Deeds of Bishops of the Hamburg Church) by Adam of Bremen in 1075 describes the archbishop Unni, who died at Birka in 936.
St Ansgar's work was the first attempt to convert the inhabitants from the Norse religion to Christianity, and it was unsuccessful.

Both Rimbert and Adam were German clergymen writing in Latin.
There are no known Norse sources mentioning the name of the settlement, or even the settlement itself, and the original Norse name of Birka is unknown.
Birca is the Latinised form given in the sources and Birka its contemporary, unhistorical Swedish form.
The Latin name is probably derived from an Old Norse word "birk" which probably meant a market place.
Related to this was the Bjärköa law (bjärköarätt) which regulated the life on market places in Denmark, Norway and Sweden.
Both terms in different forms are very common in Scandinavian place names still today leading to speculation that all references to Birca especially by Adam of Bremen were not about the same location.

Both publications are silent on Birca's size, layout and appearance.
Based on Rimbert's account, Birca was significant because it had a port and it was the place for the regional ting.
Adam only mentions the port, but otherwise Birca seems to have been significant to him because it had been the bridgehead of Ansgar's Christian mission and because archbishop Unni had been buried there.

Vita Ansgari and Gesta are sometimes ambiguous, which has caused some controversy as to whether Birca and the Björkö settlement were the same location.
Many other locations have been suggested through the years.
However, Björkö is the only location that can show remains of a town of Birca's significance, which is why the vast majority of scholars regard Björkö as the location of Birca.

Birka was abandoned during the later half of the 10th century.
Based on the coin finds, the city seems to have silenced around 960.
Roughly around the same time, the nearby settlement of Sigtuna supplanted Birka as the main trading centre in the Mälaren area.
The reasons for Birka's decline are disputed.
A contributing factor may have been the post-glacial rebound, which lowered the water level of Mälaren changing it from an arm of the sea into a lake and cut Birka off from the nearest (southern) access to the Baltic Sea.
 The Baltic island of Gotla
Birka was founded around AD 750 by either a king in order to control and expand trade or it emerged from a seasonal trading place around. It is one of the earliest urban settlements in Scandinavia. Birka was the Baltic link in the river and portage route through Ladoga (Aldeigja) and Novgorod (Holmsgard) to the Byzantine Empire and the Abbasid Califate. Birka was also important as the site of the first known Christian congregation in Sweden, founded in 831 by Saint Ansgar.
As a trading center Birka most likely offered furs and iron goods as well as craft products, in exchange for various materials from much of Europe and western Asia. Furs were obtained from the Sami, Finns, and people in northwestern Russia as well as from local trappers. Furs included bear, fox, marten, otter, beaver and other species. Reindeer antler was an important item in exchange as well as hand-carved combs made from antler. Also walrus teeth, amber, and honey were exchanged. 
Foreign goods found from the graves of Birka include glass and metal ware, pottery from the Rhineland, clothing and textiles including Chinese silk, Byzantine embroidery with extremely fine gold thread, brocades with gold passementerie and plaited cords of high quality. From the ninth century onwards coins minted at Haithabu in northern Germany and elsewhere in Scandinavia start to appear. The vast majority of the coins found at Birka are however silver dirhams from the Caliphate. English and Carolingian coins are rare.
Sources of Birka are mainly archaeological remains. No texts survive from this area, though the written text Vita Ansgari ("The life of Ansgar") by Rimbert (c. 865) describes the missionary work of Ansgar around 830 at Birka, and Gesta Hammaburgensis Ecclesiae Pontificum (Deeds of Bishops of the Hamburg Church) by Adam of Bremen in 1075 describes the archbishop Unni, who died at Birka in 936. St Ansgar's work was the first attempt to convert the inhabitants from the Norse religion to Christianity, and it was unsuccessful.
Both Rimbert and Adam were German clergymen writing in Latin. There are no known Norse sources mentioning the name of the settlement, or even the settlement itself, and the original Norse name of Birka is unknown. Birca is the Latinised form given in the sources and Birka its contemporary, unhistorical Swedish form. The Latin name is probably derived from an Old Norse word "birk" which probably meant a market place. Related to this was the Bjärköa law (bjärköarätt) which regulated the life on market places in Denmark, Norway and Sweden. Both terms in different forms are very common in Scandinavian place names still today leading to speculation that all references to Birca especially by Adam of Bremen were not about the same location.
Both publications are silent on Birca's size, layout and appearance. Based on Rimbert's account, Birca was significant because it had a port and it was the place for the regional ting. Adam only mentions the port, but otherwise Birca seems to have been significant to him because it had been the bridgehead of Ansgar's Christian mission and because archbishop Unni had been buried there.
Vita Ansgari and Gesta are sometimes ambiguous, which has caused some controversy as to whether Birca and the Björkö settlement were the same location. Many other locations have been suggested through the years. However, Björkö is the only location that can show remains of a town of Birca's significance, which is why the vast majority of scholars regard Björkö as the location of Birca.
Birka was abandoned during the later half of the 10th century. Based on the coin finds, the city seems to have silenced around 960. Roughly around the same time, the nearby settlement of Sigtuna supplanted Birka as the main trading centre in the Mälaren area. The reasons for Birka's decline are disputed. A contributing factor may have been the post-glacial rebound, which lowered the water level of Mälaren changing it from an arm of the sea into a lake and cut Birka off from the nearest (southern) access to the Baltic Sea.  The Baltic island of Gotla
Birka