Robson History Prize 2023 Applicants?

Hey,
Is anybody else entering the Robson History Prize? If so, what questions are people considering? I'm thinking about 'Why were some Jewish communities treated better than others across medieval Europe' or 'In what ways were the early modern Spanish and Portuguese empires different from each other?', but I'm still not sure if I should push myself out of my comfort zone more (these are both closely related to my EPQ so I'm not sure if I should do something from a different time period e.g. a period of ancient history or past 1700 so I can show a bit of range in my university application - I want to apply for Ancient and Modern History).

Anyways, for those who maybe have past experience with essay competitions of this sort, how many references (approximately) are expected for a 3000 word essay? This is my first time researching for something like this bar my EPQ.

And also, I know it's still early, but does anybody have links to past winning or commended entries for this prize or other similar ones? I'd just like to get a feel for the style of essay expected.

Thanks!!