Basically, justify your reasons for asking this question... i.e. Why is it worth asking. What is the interest for historians?
BUT
it could also mean (you need to check this with your supervisor) --and this is very close to the above -- that the significance of your question needs to be understood in terms of historical context. Meaning, essentially, give the background details of the events and circumstances in Napoleon's time which may have had a hand in his rise. One of these being his military prowess.
It could be both of these. Research perspective or historical perspective. They kind of merge together, actually. It is a question of focus.
So, check which with your supervisor.