This particular treasure is the symbol of office for an elected monarch, a reminder that the power of that throne comes not from inheritance, but from the people of that nation.
This is the 11th creation for what I call Treasure Tuesday; the day every week that I create a free, nonmagical object that DMs/GMs can place in treasure hoards, museums, collections, black markets, and other situations where something valuable (other than magic items) could be found.