Soon after he was engaged on an important embassy to Germany, the result of which was the treaty of Ulm, signed July 1620.
The first advance came about 74, when what is now Baden was invaded and in part annexed and a road carried from the Roman base on the upper Rhine, Strassburg, to the Danube just above Ulm.
For during the year that elapsed before he left Swabia (and whilst he sojourned at Neuburg and Ulm), and amidst his geometrical studies, he would fain have gathered some knowledge of the mystical wisdom attributed to the Rosicrucians; but the Invisibles, as they called themselves, kept their secret.
Driven from Strassburg by the authorities, after a short imprisonment in December 1531, he tried to make a living in 1532 as a soapboiler at Esslingen, removing in 1533 for a better market to Ulm, where (October 28, 1 534) he was admitted as a burgess.
His Weltbuch, a supplement to his Chronica, was printed at Tubingen in 1534; the publication, in the same year, of his Paradoxa at Ulm brought him into trouble with the authorities.