How should I structure my introduction in order to maximise my marks?

The introduction is the most important part of your entire essay as examiners will have already decided once they've read it which marking band they feel you belong in. As such your introduction needs to not only show your confidence and technique in approaching the question but also your comfort with the subject matter.

Begin your introduction by immediately stating your argument in relation to the essay question. For instance if the question was 'How important was the Treaty of Versailles in causing the Second World War' your introduction could begin with 'I believe that the Treaty of Versailles needs to be seen as the most important of all the factors which led to the Second World War because...'. Having argued why your argument is the way it is you must then go on to define any terms in the question or that you will frequently use throughout your essay. In the case of the above essay you might define what you mean by 'the September Criminals'.

For the purpose of a GCSE essay the top marks will be awarded to students who can display the structure of their whole essay in the few short sentences of the introduction. Lightly explain that other factors leading to the Second World War included the weakness of the League of Nations as well as the success of the Fascist party with particular notice on propaganda. Each of these factors can then become a paragraph later in your essay. Argue that despite these other factors it was the Treaty of Versailles that was the most important factor since, for example, it must be seen to have been the primary cause of German resentment in the 1930swithout which the Nazi party could not have succeeded.

Finally make sure that the same phrases you used in your introduction are found throughout your essay as it highlights to the examiner that your essay is highly structured and planned and therefore makes it deserving of the highest marks.