He advanced towards the Upper Rhine river and in 916 occupied the city of Basel .
Rudolph II attempted to enlarge his realm by attacking the adjacent territories of the German stem duchy of Swabia in the northwest .
Rudolph II advanced towards the Upper Rhine river and in 916 occupied the city of Basel .
Rudolph II attempted to enlarge his realm by attacking the adjacent territories of the German stem duchy of Swabia in the northwest .