TIK recently put out a very interesting video on the history of the German revolution of 1918 and the context of how the socialists gained power then split into multiple groups during the power struggle in the aftermath. This leads directly to how Hitler conceived of National Socialism, and by putting things in this context it makes a lot of World War 2 make more sense. It is very much worth watching. (And don’t be put off that its title mentions the Weimar hyperinflation or that it’s episode 2, it’s not really about either and stands very much on its own.)