The man who finally assumed the mantle of Führer was a somewhat unlikely candidate: Adolf Hitler, a native Austrian who wasn't even a German citizen until 1932, shortly before he ran for president of Germany. Hitler lost that election, but less than a year later, Paul von Hindenburg, the man who had defeated him, tasked Hitler with forming a coalition government.
Although Hitler's party, the National Socialist German Workers' Party, was the largest in the Reichstag, until January '33 most other political forces had shunned the Nazis due to the vehemence of their policies, the deification of their own leader, and their professed contempt for parliamentary government.
The conventional wisdom in early '33 was that Hitler and his circle of political amateurs would soon be gobbled up by their more experienced coalition partners from mainstream conservatism.
But Hitler and his cohorts confounded their political adversaries - not for the last time. The Nazis quickly set about to consolidate their power, using all possible components of the state security apparatus to stifle opposition and silence or eliminate all perceived enemies. Within a year, the sometimes cacophonous multitude of parties of the Weimar Republic had been reduced to the dictatorial drone of a single party with full control of the nation.
The next 12 years form that portion of German history with which you are undoubtedly most familiar. Following early stunning successes with domestic economic problems, Nazi Germany launched its expansionist foreign policy, first redressing German territorial grievances with the treaty that ended the First World War, then snatching bits and pieces of their neighbors - when not gobbling them up whole.
At home, the Nazis launched vicious hate campaigns against Jews, Gypsies, and homosexuals, as well as political opponents. All these groups found their civil rights progressively stripped away and most would soon fall victim to mass murder when the Second World War came and the extermination camp system had been set up.