Vikings invaded Britain because the land ( Scandanavia ) was REALY rocky and not fertile , which means that they can’t grow crops. Once they found out that Britain was fertile , had lots of riches and they can make good resources. The Vikings came in their longboats from Scandanvia to Britain. They all had to work as a team. They first attacked a monastery in lindifarne. They attacked the monastery first because they had all their treasures and because they wanted slaves to work for them. If the monks did not agree the tree through the into the sea.