For the first time, the place is mentioned as a donation in connection with the founding of Göttweig Abbey by Bishop Altmann von Passau. The surviving from the late 11th century place name Mulibach points to a body of water, where a mill is located: Mühlbach. The stately Krotenmühle south of the village is now decayed. The original Veste Mühlbach was destroyed in the 15th century. Today’s Mühlbach Castle dates from the late Renaissance. After the extinction of the family Mühlbacher as the owner of the estate, among others, the lords of Walsee, the lords of Hofkirchen and finally the counts Gudenus were the owners of the place. After the reforms 1848/1849 Mühlbach constituted 1850 to the independent municipality and was assigned to the administrative district Ravelsbach until 1868.
source in german: https://de.wikipedia.org/wiki/Mühlbach_am_Manhartsberg