History is concerned with significant changes such as the outbreaks of wars, new technological inventions and major shifts in public attitudes. Human societies experience major changes in a context of overall continuity. Write your extended essay by describing some major changes that occurred against the background of the overwhelming continuity of the pre-existing society. These should be significant changes that took place despite strong resistance from the status quo (see Reference 2).
An extended essay provides you ample space to explore multiple causes of your chosen historical event. Nothing in history happens for just one simple reason. Possible causes for significant changes include economic and technological factors, the organization of political and social groups and the prevailing ideas of the times. Ideas can be the values and attitudes of the people as well as the specific issues that were being debated formally during the period under study.
Certain individuals throughout history have had a profound impact on the major events of their time. They may have been elected leaders or have had more informal influence over other people. Abraham Lincoln, for instance, had a great impact on the preservation of the Union, while Martin Luther King Jr. influenced society without winning formal political office. Choose an interesting individual who had a major impact on events, and write about the individual's principles and personality, looking at both his virtues and vices.
Interpreting historical periods with the values and beliefs of the present misrepresents and obscures the past. One sure way to find an interesting historical perspective is to learn about the cultural habits, institutions and beliefs of the people you are writing about. It is a difficult task to learn about the context of a historical society, but your consequent understanding will result in an interesting research topic for an extended essay. Just be sure that you limit your research to the context of a single society or smaller group of people rather than trying to describe multiple factions in a single essay.