Copenhagen's founding has traditionally been dated to Bishop Absalon's construction of a castle on the small island of Slotsholmen in 1167 where Christiansborg Palace stands today. Recent archeological finds indicate that by the 11th century, Copenhagen had already grown into a small town with a large estate, a church, a market, at least two wells and many smaller habitations spread over a fairly wide area. Many historians believe that the town dates to the late Viking age, and was possibly founded by Sweyn I Forkbeard. From the middle of the 12th century it grew in importance, after coming into Absalon's possession, who fortified it in 1167, the year traditionally marking the foundation of Copenhagen. The excellent harbour encouraged Copenhagen's growth until it became an important centre of commerce. However it did not become the nation's capital until the middle of the 15th century, and the archbishop still has residence in Roskilde.
The city's origin as a harbour and a place of commerce is reflected in its name. Its original designation, from which the contemporary Danish name is derived, was Køpmannæhafn, meaning "merchants' harbour" or "buyer's haven" (cf. German "Kaufmannshafen"). The English name for the city is derived from its Low German name, Kopenhagen. The element hafnium is also named for Copenhagen, whose Latin name isHafnia, derived from the city's original name, Hafnæ ("harbour"). The bacterium Hafnia is also named after Copenhagen, being coined in 1954 by Vagn Møller of the Statens Seruminstitut in Copenhagen.
As the town rose in prominence, it was repeatedly attacked by the Hanseatic League. In 1254 it received its charter as a city under BishopJakob Erlandsen. During 1658–59 it withstood a siege by the Swedes under Charles X and successfully repelled a major assault. In 1711 theplague reduced Copenhagen's population of about 65,000 by one-third.
On 2 April 1801 a British fleet under the command of Admiral Sir Hyde
