The Viking Age is the period that the Danes often can be heard to talk about with a certain pride, perhaps because Denmark then experience a brief heyday of big-power status. And even to this day traces and tangible evidence of the Vikings can be experienced all over Denmark.
The fact remains that the three viking centuries changed Denmark fundamentally. From being an almost unknown heathen area Denmark had by the end of the period developed into a well-defined kingdom belonging to the European Christian society.

Traditionally the Viking raid on the Lindisfarne Monastry in 793 is used as the date of the beginning of the Viking era, and the year 1042 when King Harthacnud died is mentioned as the termination of the era.

Brutal seafigthers
The word Viking is seen on several Scandinavian runic stones in the context of 'one fighting at sea' or 'battle at see'. And indeed, seaworthiness and competent seamanship were the basis of the heyday and unification of the island realm of Denmark and a prerequisite of the numerous Viking cruises into other parts of the world. Sweden, Norway and Denmark had each their own sphere of interest matching their location.

For the Swedes it was the Baltics from where they proceeded down the Russian rivers to the Black Sea. The Norwegians comprised the Atlantic Isles, Greenland and Iceland, Scotland and Ireland. The Danes sailed along the coast of western Europe and to east England. They disembarked as traders, buccaneers or colonisers - whichever the scenario might recommend.

Denmark named at year 800
The viking ships can be devided into two categories: merchantmen which were tall and wide in proportion to their length, open amidships, and warships which were low and narrow with a deck running full length of the ship. They were a combination of sail and row boats. Both categories were built with clinkered planks. The two oldest Danish towns Ribe and Hedeby (Haithabu) date back to the early Viking era, and their location made them important as the gate to northwestern Europe and the southwestern junction of the Baltic trade.

The territory which was later to constitute medieval Denmark was to all appearances more or less unified around the year 800 by a strong central power. The text of the smaller Runic stone erected at the church at Jelling specifically states the name 'Denmark' (hence called the baptismal certificate of Denmark).

King Harald likewise placed a memorial stone in Jelling which marks the official farewell of Denmark to the ancient gods. Most likely Harald was also the promotor of the construction of the four large circular castles strategically placed in various locations in Denmark. The common feature of the castles was the circular ramparts protecting a barracks-like military installation.