Martin Luther nailed his "95 theses" to the door of the Catholic Church. This impacted the way people thought about religion, and encouraged them to question tradition.
World War 1
During the age of enlightenment, a rush of intellectual and philisophical ideas came into the common areas. Literacy rate increased dramatically as the printing press allowed for easier acess of books to the people.
World War 2
The scientific revolution took insperation from the enlightenment, whilst exploring modern scientific theories that impact our world today. That includes the scientific method, the helio- and geo- centric theories, laws of motion and many more.
The assassination of archduke Franz ferdinand of Austria-Hungary lead to the begining of WW1. The Treaty of Versailles which was used to end WW1 would set up the stage for WW2.
WW2 started with Hitler and Stalin decided to become allies to invade Poland. Hitler soon betrayed Stalin and went on to control most of europe. He murdered over half of the jewish population. The war ended with the U.S. bombing Hiroshima.
The cold war lasted from 1945 till 1990. There was no actual fighting, only diplomatic talks and arming of weapons. There were a lot of very close calls and WW3 almost occured, but we are still here today waiting to see how it all plays out.