how did the authorization practiced before the 20th century different from the totalrizm that arose during the 20th century

Authoritarianism before 20th century can be categorized in to two. Socratic authoritarians believed that Monarchy is absolute and poor people, Farmers and craftsmen supported the political, economic and personal lifestyle of the monarch. Class system emerged and disparities based on clan, race and ethnicity was evident.

In Modern authoritarianism, the dictators developed ideologies which would be followed by many otherwise these clever rulers would employ death penalty and mass homicides to uphold their supremacy.

Totalitarianism ensures despotic rule. After 20th century, this military rule was despised as there came an enlightened era which made people to think the need for liberty as it's the god given right to live free.