With my own path to the British throne being somewhat obstructed, I thought that today I’d look the heir apparent, His Royal Highness The Prince of Wales. (This is of course not intended as any comment on the continuing reign of Her Majesty the Queen.)
Should Prince Charles ascend to the throne, he’ll get to choose his own regnal name. Frankly, I think that’s just a cool idea. He could theoretically choose any name he wanted, but I suspect we shouldn’t expect a King Bobcat or any such.
Below is what he would be called if he chose any of his four given names.
The Usual Poll 
Personally, I’d go for Arthur II, lol.