During his episcopate, Duke Tassilo II presented Innichen to the Abbot of Scharnitz. With the newly acquired territory, Freising gained a port of entry into Carinthia, and the diocese soon acquired possessions also in Styria and Carniola. Atto, Abbot of Scharnitz, also Archbishop of Freising (784-810), zealously undertook the task of Christianizing the Slavs of the Pustertal. On the summit of the mountain upon which Freising cathedral stood he erected a second Benedictine monastery under the same government as the first. During his time, the diocese was made suffragan to Salzburg. Hitto (811-34) made a visitation of his diocese; he installed a provost and church on the mountain and six secular canons in the church on the mountain Weihenstephan near Freising.

During the episcopate of his successor Erchambert (835-54),a deed of gift for the first time mentions cathedral canons, who were not monks (842 and 845), the cathedral chapter being thereafter composed of monks and canons. Under Bishops Anno, (855-75), Arnold (875-83), and Waldo (883-903), brother of Bishop Salomo of Constance, the monastic element in the cathedral chapter gradually withdrew; the Benedictines of the cathedral mountain seem to have abandoned it and to have established themselves at the foot of the Weihenstephan. Waldo rebuilt the cathedral, which had been burned down; he was given jurisdiction over the neighbouring Abbey of Moosburg, and received from Louis the Child in 906 the right of free choice of bishops for the cathedral chapter.

The Hungarians gained an entry into Bavaria and destroyed almost entirely the spiritual life of the country.