North Germanic peoples
Vikings were also active in Francia. Some of these Vikings would sail through the Strait of Gibraltar and pillage the coasts of the Mediterranean Sea. In the early 10th century, a group of Vikings under the leadership of Rollo settled in Rouen, France, and established the Duchy of Normandy. The descendants of these Vikings, known as the "Normans", would in the 11th century conquer England, Southern Italy, and North Africa, and play a leading role in launching the Crusades. Sub-groups of the Normans include Anglo-Normans, Scoto-Normans, Cambro-Normans, Hiberno-Normans and Italo-Normans.
History of the North Sea
The attack on Lindisfarne in 793 is generally considered the beginning of the Viking Age.
For the next 250 years the Scandinavian raiders of Norway, Sweden, and Denmark dominated the North Sea, raiding monasteries, homes, and towns along the coast and along the rivers that ran inland. According to the "Anglo-Saxon Chronicle" they began to settle in Britain in 851. They continued to settle in the British Isles and the continent until around 1050.