Nation-states developed in the west in the period from 1500 to the present because

Nation states begun to develop in Europe from 1500s because a number of monarchs began to consolidate power by waning the feudal nobles and to bring all the people under their territories under unified rule. This was based on their language and it sparked nationalism, as monarchs stimulated their subjects to be loyal to their newly established nations.

monarchy doesn’t have to have the hereditary element. there have been elective monarchies in the past where you choose your king-for-life and when he dies elect someone else for the job.

explanation:

hitler's  "rise" can be considered to have ended in march 1933, after the reichstag adopted the enabling act of 1933 in that month. president paul von hindenburg had already appointedhitler  as chancellor on 30 january 1933 after a series of parliamentary elections and associated backroom intrigues.