Hitler was an aspiring artist till he signed up for the army. Hitler was originally from Austria but the Austrian army would not take him so he signed up and was accepted into the German army. When Germany surrendered in world war 1 Hitler made it his personal mission to avenge it. Hitler blamed the Jews and other inferior races for all of Germany's problems and that's where everything basically went wrong.
Hitler came to power by using propaganda and making promises. He appealed to the young, the middle class, and lower class. He was appointed chancellor in 1933 and the people of Germany thought they found a savior to take them out of the dark times.
Hitler brainwashed his people into believing all of the things he did. He trained kids to ruthless killing machines. If his people stood against his beliefs or questioned him they would be killed
Hitler wanted to expand Germany so that his people would have more "living space". Hitler wanted to get rid of all inferior races. Hitler believed that without Germans the world would end.
Used propaganda, terror, etc to control his people. Anyone who opposed him was killed so he ended up striking terror into the hearts of his people.