Heinrich Himmler was the Reichsführer - or Commander - of the Schutzstaffel, or the SS, the military arm of Adolf Hitler and his Nazi Party.
Born in Munich in 1900, Himmler's father was a respected professor and his mother, a devout Catholic. He was not a very strong child physically and was always sickly. He worked hard at school but sadly didn't do very well, and in 1917 he joined the army, training as a gunner. He didn't finish army training and never saw action during World War I, though he does lie about this later in his career.
As early as university, he was a vocal anti-semite and was a nationalistic militarist who took great pride in Germanic culture and traditions. He then became a member of Hitler's brand new Nationalist Socialist Party (the Nazi Party) in 1919, its radical far-right ideologies meshing perfectly with his prejudice.
At first, he was only a volunteer, travelling the countryside to talk about the Jews and why they were "evil." From there, he was given small jobs like editing their newsletter and checking their secret armories around Germany (because he had a motorcycle). He joined the newly formed SS, a bodyguard unit for the VIP Nazis. In 1926, he became the Deputy Propaganda Chief and worked with Joseph Goebbels.
He quickly rose through the ranks, catching Hitler's eye by reorganizing the SS so only the best, strongest, and most Aryan, Germanic and pure-blooded were allowed to join. He established the Nazi counterintelligence unit and, in 1934, set up the first concentration camp - Dachau - which would become the model for all the others to come.
At this point, he now controlled all the German police forces and the Gestapo. With Hitler in supreme control, anti-semitism reigned supreme. Jews were not allowed to marry non-Jews, non-Aryans had their German citizenship revoked, and most were sent to the ghettos and blocked off from the rest of the population.
When World War II broke out in earnest, the Nazis executed thousands of people via death squads. It was messy, unsanitary, took too long, and affected the German soldiers' psychological state. Being meticulous and process-oriented, Himmler helped design "The Final Solution", which was an efficient - and modern - mass-killing and extermination process of Jews and all other prisoners - including gypsies, people of color, homosexuals and more.
Despite being high up in the party, Himmler realized that Hitler was losing and secretly reached out to the Allies. This eventually led to Hitler's suicide when the Russians were about to storm Berlin. Upon Hitler's death, Himmler pretended to be a regular German soldier. He was caught and committed suicide by biting down on a cyanide tooth cap while in captivity.
Himmler's legacy is a gruesome, inhuman and evil one. Maybe this was his way of compensating for being a blandly ordinary and even underwhelming human being early in his life.