Ban was title of medieval rulers of Bosnia and Wallachia. It is sometimes translated as viceroy but that is not accurate.

It is thought that this word originates from Sarmatian "Bajan"; it also bears similarity with Khan.

Teritory over which a ban rules is Banovina (in Bosnia) and Banat (in Wallachia).

Ban was also title of province administrators in Hungary; each of the provinces was called Banat. The title doesn't bear nearly as much weight as medieval one.

Ban was also title for province administrator in Kingdom of Yugoslavia; each of the provinces was also called Banovina. The weight of the title was not nearly similar to medieval one.