Rudolf m. Old Saxon hrōth, Old High German hruod 'fame' + Old High German wolf, Gothic wulf 'wolf'.
The name of an 11th C king of Arles, a 13th C king of Germany, a 13th C duke of Austria, a 14th C king of Bohemia and Poland, a 14th C duke of Austria, and a 16th C Holy Roman emperor.
The name is sometimes confused with forms of Ralph, of similar etymology.