pronounce, that you had to call the guy brother of Jared, if it is in your own language? I mean, even real names like Arnold Schwarzenegger are simple enough to remember and use for us that we don't go around calling him the Husband of Maria.

To call the guy the brother of Jared only makes sense if you made the name up on the fly, say for a story you were writing, and couldn't remember it, so you left Brother of Jared in as a place holder that you later forgot to take out.