When I search for coins of a monarch, say Carlos III of Catalonia, I'd like to also get the coins issued by Karl VI of Austria - it's the same person.
I suppose for coins of Elizabeth II issued in all the Commonwealth it's a bit dull, but for older coins, this would be an interesting feature.
The Search should show the results for Carlos III at the top, as they are, and then show "Coins issued by X in other states:"

Or maybe just give a link to the other search results, a bit like how the coin references work now.
Best
strato