Question

how was history divided into periods

Answer 1

We divide history into different parts because of the voluminous nature of historical events. Consequent upon this it is impossible for historian to study everything at a time. How would you look at a historical work that study the ancient, mediaval and modern history of Europe or the history of Africa, China. Latin America etc in a single document and without making reference to their different historical circumstances? In a nutshell for easy study historical events cannot be studied without compartmentalizing them according to periodization and places of event.