Mad King George the III, who was likely bipolar (and/or had porphyria, which can affect behavior), pulled off some doozies, but his almost 60 year reign is now thought of as fairly successful overall (there's controversy, of course).I've been wondering. Is there anyone in history that was extremely powerful/famous that became eccentric and then backed to normal again?
(including any emperor if someone has the example)
Perhaps you have some other examples in mind.