First we need to work out what the question is actually asking - they're looking for you to assess what was IMPORTANT about this rebellion in particular. That suggests that we need to think about some potential causes and consequences of the Essex rebellion, and why Essex's actions had an impact on Elizabethan England. We need to mention multiple factors, and analyse them in a sustained way - e.g. by looking at the same factor from different angles - in order to get into the top mark band for this question.Some potential reasons why the rebellion was important might be that Elizabeth ultimately retained power and had Essex executed, which is important because it shows that even towards the end of her reign, she was still in control. However, the fact that so many people rallied behind Essex shows that she was not universally approved of; thinking about opinions of Elizabeth in this way will help to boost marks. We might also think about how we can link the Essex rebellion to Elizabethan England more generally - for example, the fact that the rebellion is important because it demonstrates the widespread dislike of Robert Cecil, Elizabeth's favourite, at the time. We could also consider the cultural importance of the rebellion; Shakespeare's new play Richard II (a play about the dangers of favouritism) was performed the night before the Essex Rebellion, which is important because it shows that plays could have political connotations in this period.