How do you structure a history essay?

An IB history essay will typically be composed of three parts: introduction, main body (which will usually have around three paragraphs) and a conclusion. When you're planning your essay you mainly want to focus on making sure you are actually answering the question that is being asked. So, for example if the question is "Assess the factors which led to India's independence from Great Britain in 1947," you will not only need to make sure you are focusing on the reasons why India achieved independence but also on analyzing these reasons in a critical way to answer the "assess" part. Thus, in your introduction you want to provide a little bit of background on the historical event the question is asking about - focus on India's independence, some basic information about how it came about and what effect it had on following events. But, the main part of your introduction should be narrowing down the question if necessary (for example, you can say that you will mainly focus on the events that took place in the 1900s when considering factors leading to their independence) and mainly it should include the thesis for your essay - your thesis should be a clear and concise summary of what your essay will be arguing. The thesis should be considerably broad but still include some specific details and should include all of the arguments you will be making in your main body.
Your body will have approximately three main paragraphs, therefore, you should usually aim to have three main points that support your thesis and answer the question. Each body paragraph should have a topic sentence that clearly summarized the argument of that paragraph. Similarly, each paragraph should also have a short concluding sentence at the end, in which you summarize all the point you made in the paragraph once again but also in which you tie that paragraph back to the original question and make sure that your paragraph is related to your thesis and is answering the question. In your paragraphs you want to focus on making your own argument and using historical events to support that argument - avoid being vague, use specific names and dates of events and explain how those events affected India's path to independence and what effect they had. Don't be afraid to use historiography as well, mention historians who have a similar view as you to support your argument or who disagree with you to provide the critical analysis that the essay requires. Lastly, your essay should include a conclusion, which should not be longer than a paragraph and should sum up everything you talked about in the body. So, in the conclusion you should focus on summarizing all of your previous arguments and making sure that they are answering the question.