Charles had recently been given the temporary field rank of cadet - lieutenant, but this was only a field rank, and he would be a cadet-ensign again once the exercise was over.
Gold medals were instituted in Britain for Royal Naval commanders in the 1790s and, after 1806, for military officers of field rank and above, who distinguished themselves in specific actions.
Eventually, you can earn enough for an increase in field rank, which brings with it upgrades to certain battlefield skills, such as an enhanced rate at which stamina may be replenished, or better shooting accuracy.