<span>The case of Marbury v Madison was a landmark decision due to the fact that it upheld the limited powers of a specific branch of government, and ensured that no such cabinet official would be able to be above the law by implementing the concept of the writ of mandamus.</span>
Answer;
Vikings accepting Christianity
Most important event during the period of European invasions is the vikings accepting Christianity.
Explanation;
At the beginning of the Viking Age, almost the entire population of Scandinavia was pagan, however the vikings had many Gods and it was not a big deal for them to accept the Christian god alongside their own.
The conversion of Vikings to Christianity occurred without violence, by the end of the Viking age most vikings had become fully Christian and were baptized and buried in that faith.
It helps us better understand the choices of the people before us. If we don't learn about its history then the lives lost fighting would be worthless.