St Rabanus Maurus presenting his work to Pope Gregory IVSaint Rabanus Maurus Magnentius (c. 780 – 4 February 856), as a Frankish Benedictine monk, the archbishop of Mainz in Germany and a theologian. In his spare time he authored the encyclopaedia De rerum naturis (On the Nature of Things) and treatises on education, grammar and  the Bible.
Rabanus was born of noble parents in Mainz. He was a professed monk having entered the Benedictine abbey at Fulda. He studied there under Alcuin. His academic career included the responsibility of being the “Praeceptor Germaniae,” or “the teacher of Germany.” That is, Rabanus is considered one of the most prominent teachers and writers of the Carolingian age.
The data of his ecclesiastical career shows that in 801 Rabanus was ordained deacon and in 814 ordained priest. After a series of disagreement and complaints about his work, he faced exile but in 822 was elected abbot of his abbey. In 847, Rabanus  succeeded Otgar as the archbishop of Mainz. He died at Winkel on the Rhine in 856.