Duke Ulrich had passed some time in Switzerland, France and Germany, occupied with brigand exploits and in service under Francis I of France; but he has never lost sight of the possibility of recovering Württemberg and about 1523 he had announced his conversion to the reformed faith.

His opportunity comes with the outbreak of the German Peasants' War.

Posing as the friend of the lower orders and signing himself "Ulrich the peasant", his former oppressions are forgotten and his return is anticipated with joy.

Collecting men and money, mainly in France and Switzerland, he invades Württemberg in February 1525, but the Swiss in his service are recalled owing to the defeat of Francis I of France at Pavia; the peasantry are unable to give him any serious support, and in a few weeks he is again a fugitive.