Viking raid warfare and tactics
Vikings were members of tribes, originally from Scandinavia, of Norse ancestry, who gained a reputation for their raids and piracy in many parts of Europe, especially England, Ireland, and Frankish territories. The term "Viking Age" refers to the period roughly from 793 AD to the late 11th century in Europe. In this era Viking activity started with raids on Christian lands in England and eventually expanded to mainland Europe, including parts of present-day Russia. While maritime battles were rare, Viking bands proved very successful in raiding coastal towns and monasteries due to their efficient warships, and intimidating war tactics, skillful hand-to-hand combat, and fearlessness. What started as Viking raids on small towns transformed into the establishment of important agricultural spaces and commercial trading-hubs across Europe through rudimentary colonization. Vikings' tactics in warfare gave them an enormous advantage in successfully raiding (and later colonizing), despite their small population in comparison to that of their enemies.
Naval warfare
In the 8th century the Vikings appeared, although their usual style was to appear quickly, plunder, and disappear, preferably attacking undefended locations. The Vikings raided places along the coastline of England and France, with the greatest threats being in England. They would raid monasteries for their wealth and lack of formidable defenders. They also utilized rivers and other auxiliary waterways to work their way inland in the eventual invasion of Britain. They wreaked havoc in Northumbria and Mercia and the rest of Anglia before being halted by Wessex. King Alfred the Great of England was able to stay the Viking invasions with a pivotal victory at the Battle of Edington. Alfred defeated Guthrum, establishing the boundaries of Danelaw in an 884 treaty. The effectiveness of Alfred's 'fleet' has been debated; Dr. Kenneth Harl has pointed out that as few as eleven ships were sent to combat the Vikings, only two of which were not beaten back or captured.