The Nazis tried to seize power by force in November 1923 (called the Beer Hall Putsch), but were thwarted by the Munich police. Hitler was
convicted of high treason and sentenced to prison, where he served about a year. During that time, he began to write Mein Kampf ("My Struggle"), which later became the second Bible in Nazi Germany. Hitler resolved to achieve power legally, and after a series of events too numerous to detail here, was appointed Chancellor of Germany by President von Hindenburg on January 30, 1933.
Over the next 6 years, Hitler undertook a series of measures designed to rid Germany of its obligations under the Treaty of Versailles (imposed on Germany after World War I), restore the economy which had been devastated by the Great Depression, rearm the country, and acquire Lebensraum ("living space") for Germany. In Mein Kampf, he had written of the need for this "living space" which he said could only be acquired at the expense of countries to the east, notably Russia. In 1938, by a series of intrigues, Germany annexed Austria and the Sudeten portion of Czechoslovakia, and, in 1939, occupied the remainder of Czechoslovakia.
During this time, Hitler implemented a series of measures designed to eliminate the Jews from German life. Among these were gradual exclusion from most spheres of professional activity, rules as to where they could live, prohibition of marriage and other relations between Germans and Jews, economic sanctions and many others. Jews were harassed, attacked, beaten and otherwise persecuted. Many were incarcerated in concentration camps under "protective custody" orders which were tantamount to indefinite imprisonment. There they were beaten, abused and frequently murdered.
World War II began in September 1939 with the German attack on Poland. By mid-1940, Germany had conquered Poland, the Netherlands, Denmark, Norway, Belgium, and France, and had Britain at its mercy. At this time, Hitler began to think about attacking the Soviet Union, with which he had concluded a non-aggression pact just before the outbreak of the war. His motivation was both to acquire the "living space" he had talked about in "Mein Kampf" and to exterminate Communism, which he saw intertwined with Jewry. The attack took place in June 1941.
It was roughly at this time that Hitler ordered the extermination of the Jews, which the Nazis called die Endlösung ("the Final Solution"). There is some debate as to exactly when the order was given (since no written order has been found), but most experts place it in mid- to late-1941. It most likely was an evolving process.
In any event, concurrent with the invasion of the Soviet Union, Einsatzgruppen under the overall direction of Heinrich Himmler, Leader of the SS, followed the German Army into the Soviet Union and began to shoot Jews - men, women and children - where they were found. Starting in late 1941 and early 1942, stationary killing centers were set up in various locations, where Jews were gassed with hydrogen cyanide or carbon monoxide. By the end of the war, approximately 6 million Jews had been shot, gassed, or worked to death.
The fortunes of war turned irrevocably against Germany at the end of 1942 and it was all downhill from then until the end of the war in 1945. Nonetheless, the killing of the Jews continued right up to the final days. With Soviet forces approaching the underground bunker in Berlin where he had been holed up since early 1945, Hitler committed suicide.