Spanish History Events

Three events in world history that affected 2 or more groups of people?
I need to write six paragraphs on the prespectives on three different occassions of 2 groups of people each…
It’s frusterating…
Example: How the native americans felt when the spanish came to america and how the spanish felt when they thought they discovered it.
I need help…. World history is not my best subject at all.
1) The Nazi Holocaust. (1940-1946) It affected the Jewish, Germans, American Soldiers who discovered Concentration camps.
2) The Roman abandoning of Britain (410) changed the the Roman-Bretons, Picts, Welsh and opened the land for invasion from Danes and Norwegians.
3) The Comanche Campaign (1867-1875) It affected the lives of over fifty tribes of Native Americans and the Anglo-Americans in at least 5 states.