Answer:
They sailed many rivers on Europe on longships
Step-by-step explanation:
The Vikings were a group of Germanic people from Scandinavia. As they did not had nice conditions for agriculture, they were mostly tied to the sea, be it for food, trade, explorations, or warfare. They were excellent warriors, and once they grew strong enough, they started to move along the coasts and rivers in the rest of Europe. The Vikings emerged to power in just the right moment, as the majority of Europe was relatively weak, so they managed to take over lot of coastal areas on the continent, important ports, and sailing through the larger rivers and controlling them and the trade through it. That made them very wealthy, and they also had a reputation as being giants and the best warriors, all of which was going well in their advantage.