In the 13th century, Isny's merchants built a fortification system to protect the town from marauders and rival feudal rulers.
The town is still partially surrounded by the city walls and moat that were built during these early turbulent times.
After three centuries of domination by feudal lords and territorial rulers, Isny's middle class was able to purchase the town's independence in 1365.
Isny emerged from the war largely undamaged, and has since become a popular destination for vacationers and resort-goers.
Aicher responded with a set of 128 black and white pictograms which, while initially controversial, are now regarded as forward thinking and are still used to promote the town.