The residents of Erpfting were faced with severe distress when the turmoil of the Thirty Years' War raged across their region. In addition to the ravages of war, the black death, the plague, raged, which in Erpfting wiped out almost the entire population within 10 years. In the midst of this need, Pastor Sießmayr placed a picture of the painful Mother of God on an oak tree in the nearby sparse forest of Erpfting. The people ceaselessly made a pilgrimage to the image of Mary on the oak tree and pleaded for an end to the disaster soon. In fact, the plague disappeared the following year. But the war was not over yet. In 1632 the notorious Swedes attacked the village and captured the miller Johann Zech. As they passed the oak tree in question, he turned to Our Lady pleadingly and asked for her assistance. The Swedes angrily drew their swords and wanted to slay the man on the spot. But when he reached out, the blades shattered over his head. The soldiers ran away in horror. Pilgrims from all over the area then flocked to the “Maria Eich”. In 1638 a wooden chapel was built in which the miraculous image of Our Lady was erected. Finally, in 1696 the construction of a large Marienkapelle was initiated by the Wessobrunn master builder Johann Schmuzer, who shortly before planned the pilgrimage church of Vilgertshofen. In 1762 the chapel was decorated with the ceiling painting "Judith with the head of Holofernes" by Johann Baader, the well-known "Lechhansl".