At its latest, in the 12th century, the area and its core settlement on the north end of Mönchsberg took the name Mülln.
Mülln once possessed 5 city gates, which stood partially prior to 1480, the time of the second city fortification of the city Salzburg: As of 1835 the Parish of Benedictine Abbey Michaelbeuern has incorporated the Augustine Order "to our dear women of Mülln" („zu Unseren Lieben Frau zu Mülln“).
Archbishop Gebhard at this time had commissioned the dilapidated altar of the Marien Chapel to be restored.
Mülln possibly became the oldest Salzburg suburb to be fortified and militarily secured, complete with walls and guard towers.
Also the church, at the time possibly found on the main street, was included as well.