 Hearing of Haymo's promotion, Rabanus Maurus, his old friend, gave him at great length—in a work entitled "De Universo" and divided into 22 books—advice that would help him in the discharge of the episcopal office.In compliance with Rabanus's suggestions, Haymo stood aloof from the Court of King Louis the German, did not entangle himself in the affairs of the State, preached often and lived solely for the welfare of his diocese.The only public assembly which he attended was the Council of Mainz, held in 847 for the maintenance of the ecclesiastical rights and immunities.