In 1056, Welf I, Duke of Bavaria, founded a Benedictine monastery on the Martinsberg, overlooking the village of Altdorf, an inheritance from his mother. The name Weingarten ("vineyard") is documented from about 1123. (In 1865, the village took the name of the monastery to become the present town of Weingarten). He settled it with monks from Altomünster Abbey. In 1126, Henry IX, Duke of Bavaria, withdrew here after his abdication; he died the same year and was buried in the abbey church.