Ermanrich or Ermenrich (Hermanrich; born c. 814 – 874) was a Benedictine monk and court chaplain, who became Bishop of Passau from 866 to 874. He supported East Francia's expansion to the east, and likewise the expansion of the eastern bishoprics, and opposed the missionary efforts of Cyril and Methodius, who he considered intruders. This brought him into conflict with the Papacy, which supported the brother missionaries. Life Ermenrich, son of a Swabian noble family, was originally a Benedictine monk at Ellwangen Abbey. At the Monastery of Fulda he was a student of Rabanus Maurus and Rudolf von Fulda. At the court of Louis the German, Ermanrich was one of Archchaplain Gozbald's students. He became a member of the Hofkapelle, and as a court chaplain was closely connected with Abbot Grimald, in whose monastery he lived temporarily. Ermenrich enjoyed great respect both as a scholar and as a writer. In the early 840's, at the request of Gundram, court chaplain to Louis the Pious and nephew of Rabanus Maurus, Ermenrich wrote the Vita Suaolonis of Saint Solus of Solnhofen, an Anglo-Saxon missionary of Fulda. A few years later, he composed a Vita Hariolfi, a biography of Hariolf, the founder of Ellwangen Abbey, and dedicated it to his former teacher, Gozbald, a relative of Hariolf. In the early 850's Ermenrich was living at the Abbey of Saint Gall. In an extensive letter to Grimald, which was intended for a wider circle of readers, he also showed Greek knowledge and conceived a planned but not preserved metric Vita S. Galli. The Collectio Pataviensis probably does not originate from him. In 862 or 863, old Bishop Hartwig of Passau suffered a serious stroke, that left him largely disabled, and in 866 Ermanrich was chosen to succeed him as new Bishop of Passau. In his time, great efforts were made to integrate newly Christianized areas in the eastern part of the church organization of the Diocese of Passau. In 867 Louis the German commissioned Bishop Ermanrich and a numerous retinue of priests to set out for the Danube. When Ermanrich reached Bulgaria, he found the field already occupied by priests from Rome, and returned to Germany. The project failed because of the rivalry with Constantinople as to the jurisdiction over the territory of the Slavs. The rulers of Moravia and Bulgaria played off Rome and Constantinople against each other in order to maintain independence