An archdiocese in Bavaria. This archdiocese originated in the ancient Diocese of Freising. The Church of Freising dates back to St. Corbinian, who, after his consecration came in 716 to organize the Church in Bavaria. On a mountain near Freising the saint erected a Benedictine monastery and a school. He was succeeded in the government of the abbey by his brother Erembert. When St. Boniface in 738 regulated ecclesiastical affairs in Bavaria by the creation of four dioceses, Erembert was chosen first Bishop of Freising, which see was made suffragan to Mainz. The sanctuary of Our Lady, which existed on the mountain near Freising before the coming of St. Corbinian, became the cathedral, and was served by the Benedictine monks. At the time the diocese embraced the countryof the Upper Isar as far east as the Inn and south to the watershed of the Inn and the Isar. The third bishop, Joseph of Verona (747-64), established a collegiate church in Isen, and shared in the founding of the convents of Schäftlarn and Scharnitz, placing the government of the latter in the hands of Abbot Atto. The last-named foundation was particularly significant, in view of the later acquisitions of the diocese in the Pustertal.

Other important convents of the diocese were Tegernsee, Moosburg, Ilmmünster, Altomünster, Schliersee, and Rot-on-the-Inn. The learned Aribo, or Arbeo (764-84), the biographer of St. Corbinian, translated the remains of this saint from Mais to Freising and interred them in the Sepulchrum Corbiniani which he had built (765-68) in the church of Our Lady.