What should I include in my introduction of an A-level History essay?

Introductions are the most important parts of essays at A-level. While knowing your content is important, the way that you structure essays is the most crucial thing you can learn to make sure that you achieve the top marks. Your introduction sets the tone for your entire essay, so you should use your introduction to prove to an examiner that you know what you are talking about by setting out exactly what will go in your essay. There are three core components to a good A-level introduction: context, 'signposting' of themes, and judgement.
You can start by setting out a little bit of context, perhaps relating to what was going on more broadly in the period you are asked about or why this period was significant. Next, be very clear about what you will write about in each paragraph. This is known as 'signposting' and it really shows the examiner that you have a strong structure set out in your essay. For instance, "this essay will consider the success of Henry VIII's religious, economic, and foreign policies in achieving his aims". Finally, at the end of your introduction, set out what your judgement will be. For example, "this essay will argue that although his economic policy had some successes, Henry VIII's religious policy was most successful in achieving his aims". This will help you to keep your argument running clearly through your essay, rather than making a panicky conclusion at the end or sitting on the fence. It will also help you if you feel you are running out of time as you have already decided what your conclusion is going to be.