sentences:  In 614, he established Bobbio Abbey on land donated by the Lombard king Agilulf.When Columbanus crossed the Alps into Italy, Gallus remained behind and became a hermit in the forests southwest of Lake Constance, near the source of the river Steinach, and died around 646.About 100 years later, the Abbey of Saint Gall was erected on the site of his hermitage.