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.
Viking expansion
The Vikings pillaged monasteries on Ireland's west coast in 795, and then spread out to cover the rest of the coastline. The north and east of the island were most affected. During the first 40 years, the raids were conducted by small, mobile Viking groups. From 830 on, the groups consisted of large fleets of Viking ships. From 840, the Vikings began establishing permanent bases at the coasts. Dublin was the most significant settlement in the long term. The Irish became accustomed to the Viking presence and culture. In some cases they became allies and also intermarried.