The League of Schmalkalden was a
defensive league formed by
protestant states in the
Holy Roman Empire in the 16th century.
It was made up of eight princely states and eleven city states. Many protestant states did not join the league, fearing the Emperor’s wrath. This made the league weak.
When Charles V defeated the protestants at the Battle of Muhlberg, 1547 he only doled out severe punishment to members of the league.