In 1427, under Abbot Leonard Weinmayr, extensive vineyards were cultivated, which yielded, in good years, 50 000 litres of wine. The old house of the vineyard’s gardener was built in 1542 in Renaissance style. The vineyards were destroyed by Grape phylloxera, a small insect, end of the 19th century but replanted afterwards with resistent rootstock.The monastery at Kaisheim was called „carcer ordinis“ because it so rigidly observed the rules of the holy order. Therefore a house was built not far away where the monks would relax and restore their health while cultivating the vineyard. The church and the abbot’s summer residence were built around 1690. In the meantime, the monastery, because of its increasing importance, was raised to a free, sovereign state. This action meant new duties and caused the artistically-minded Abbot Celestin I, Mermos, (1751) to rebuild and redecorate the third floor of the castle in the taste and and style of the times – Bavarian Rococo style. The Bohemian painter Gottfried Bernhard Göz, who created the fresco of the Birnau monastery at Bodensee in 1750, painted another of his fresco cycles. Anton Landes from Wessobrunn created the impressive stucco ceiling and walls.
We hear of princely receptions in the monastery, of art festivals, a high point for musical art. Wolfgang Amadeus Mozart returning from Paris in 1778, met Abbot Celestin II Angelsprugger in Mannheim. The Abbot, urban, friendly and hospitable, took Mozart home to Kaisheim with him, where Mozart stayed for eleven days. We can imagine Mozart’s delight in the lovely setting of Leitheim Castle, which was the Abbot’s favourite place, that certainly has been shown to him. Less than a generation later, in 1803, Kaisheim was one of the 112 small states ordered to be secularized by Napoleon, and so ended the religious and cultural mission of the formerly important abbey.In 1816 the monastery of Kaisheim was turned into a prison and Leitheim was bought by the Count of Montperny. In 1835 his son-in-law Baron von Tucher followed. The construction of the Donautalstrasse made it possible, in spite of grave difficulties, to open the Leitheim Castle to friends of the arts and start in 1959 with the Leitheim Castle Concerts In 2008 the whole ensemble was acquired by the Messerschmitt Foundation. Subsequently the foundation built a 4 Star plus Hotel aside the castle and transformed the former vineyard gardeners house into a restaurant.