I don't know whether this is the "correct" explanation, but I think it's plausible - In a medieval setting, commoners visiting a court might believe courtiers

I don't know whether this is the "correct" explanation, but I think it's plausible - In a medieval setting, commoners visiting a court might believe courtiers dressed in fancy clothes and speaking in Latin were doing magic and performing spells. They might have no idea how things like law and government works. If those kinds of magic worked, why wouldn't magic on mountains or trees work? Especially if you were taught by wise people from the church that invisible spirits definitely existed.