granted , but you're on medieval-dark-age europe setting where if you stated that you got branded a witch or a dark art practitioner and proceed to burn at the stake ...
I wish that the Pyramids of Giza were never grave-robbed but instead all of its treasures were secure until modern professional archaeologists and Egyptology were able to properly study them, in which they can be safely displayed without ever getting ruined, destroyed, or going missing ever again.
Granted, all those wishes have to involve having anal sex (receiving) with a homeless man named Joe from Florida, who has more STDs than should even be possible given he's a virgin. Also, he's a crack addict. Have fun!
I wish for the Mongols to reconquer the entire Middle East and for it to be just one Khanate that is no longer massively violent, war-prone, or genocidal.