In most cases, the Norse Viking Age is recorded to have officially began in 793 AD with the first recorded raid through to 1066 AD, ending with the Battle of Hastings. However, these dates vary upon scholars. The Battle of Hastings wasn't exactly the end of the Viking Age, because the Norse were spread out across Europe and Viking raids continued to take place in other locations. With that said, dating the conclusion of the Viking Age is fairly generic because Viking raids were sporadic in many locations and when one area was under control, another area was being raided. Additionally, because Viking raiders weren't unified efforts and most Norsemen tended to 'vikingr' (raid) at their own whim. This places the conclusion of the Viking Age at approximately the beginning of the 12th Century-ish. This is also about the time when Norse and other Kingdoms were becoming increasingly solidified and more able to repel Viking incursions. This was also around the time when the Christianization of Northern Europe and Norse dominated lands began to take a firmer hold. So dating the exact end of the Viking Age is vague at best.
The same can be said about the approximate beginning of the Viking Age as well. Although it's officially marked by most scholars as beginning in 793 AD with the raid on the Lindisfarne Monastery, however it wasn't a new concept to go “vikingr' (raid). Viking raids were already occurring in a vast range of other areas, including France.
The most accepted official start of the Viking Age is recorded to have begun on June 8th, 793 AD when Norse raiders landed on the island of Lindisfarne and attacked the Christian Monastery located there, killing the monks and seizing the valuables. Viking raids by opportunistic Norsemen also began occurring in other locations, such as the island of Iona in Scotland in 794 AD. By 795 AD, Christian Monasteries along Ireland's coast were being raided regularly by small Viking groups for the first 40 years. After that, large Viking fleets began showing up.
Viking Raids had begun on the Western coast of Francia (France) in 790 to 800 AD. Normandy takes its name from the Viking raiders whom were called Normanii (Norsemen or Men of the North).
What made the Lindisfarne significant to mark it as the beginning was because it was the earliest official recording of a raid and it had caused much stir in the Christian world because they attacked an unarmed religious area and killed all the monks. The Viking raids were sporadic, yet very violent when they occurred. It was during this time that marked the beginning of the Viking Age of Invasion by means of the Longship
It was during this time when England was relaxed with isolated communities along the edges of coasts, islands, peninsulas, and other waterway inlets. These communities were unguarded without a second thought to any dangers from the sea. This complacency opened the door to Norse raiders as being easy pickings. There...