Here Gallus fell sick and was put in charge of Magnus and Theodore (Magnoald and Theodo), two clerics living with Willimar, while Columbanus proceeded to Italy and founded Bobbio Abbey.

[1] About this time a priest of the Diocese of Augsburg, named Tozzo or Toto, came as a pilgrim to the grave of Gall and invited Magnus to accompany him to the eastern part of the Allgäu.

He penetrated into the wilderness, then crossed the river Lech at a place still known as St. Mangstritt ("footstep of Saint Magnus") and built a cell, where afterwards the monastery of Füssen was erected, and where he died.

A tiny splinter of the breast bone was sent from St Gallen to Füssen and this is now located in a large glass cross hanging above the main altar.

When in 851 Bishop Lanto transferred the relics to the newly erected church of Füssen, this "Life" is said to have been found in a scarcely legible condition, and to have been emended and re-written by Ermenrich, a monk of Ellwangen.

Its location on the old Via Claudia Augusta from Augsburg to northern Italy gave it strategic importance, and the Abbey received support from Pepin the Short.

[4] Magnus is the patron saint of the Allgäu, von Füssen, and Kempten; and is invoked for the protection of cattle; and against eye diseases, snakebite, worms, rats, mice and field insects.

[4] The veneration of Saint Magnus was carried to the New World by the German Catholic peasant pioneers whom Francis Xavier Pierz had persuaded to settle in Central Minnesota following the Treaty of Traverse des Sioux in 1851.