The original nucleus of the complex was established in 769, when Duke Tassilo III of Bavaria gave to Abbot Atto of Scharnitz extended estates lands in the Puster Valley stretching from the Gsieser Bach at current Welsberg eastwards down the Drava to Anras, called India, provided that a Benedictine convent would be founded here to convert the pagan Slavs who had settled in the principality of Carantania.
When the monastery was turned into a college of canons, the church was entirely rebuilt from about 1140;[1] of this edifice today the external walls, the piers, the apses and the crypt remain.
A second reconstruction was carried out from around 1240,[1] when the vaults of the crypt and the nave, the transept and the dome at the crossing were added, including the frescoes with the History of Creation.
Candidus and Corbinian, patron saint of the Diocese of Freising, to which the abbey still belonged at the time.
In 1969[1] a restoration was held, removing the few minor additions it had received during the centuries (especially in Baroque times), in particular re-discovering the crypt's frescoes, which had been covered with a layer of plaster.