Why do some characters from medieval fantasy settings have the name of a place attached to their name as a title? For example Geralt of Rivia.

by Vi0letBlues

Did this really occur back then and if so, is it a common thing or is it reserved only for important people, and why?

CaptainRhino

There's always more that can be said, but you might be interested in this thread about the origin of modern surname conventions, with answers by u/lord_mayor_of_reddit and u/talondearg