Heilbronn League

Heilbronn League
1633–1635
Founding of the Heilbronn League, April 1633
Founding of the Heilbronn League, April 1633
Common languagesFrench and German
League Director 
• 1633–1635
Axel Oxenstierna
Historical era1633 to 1635
• Established
23 April 1633
• Dissolved, following the Peace of Prague
30 May 1635

The Heilbronn League was formed in the Free Imperial City of Heilbronn, on 23 April 1633, during the Thirty Years' War. Led by Sweden, it brought together various Protestant states in western and northern Germany. It was supported by Saxony and Brandenburg-Prussia, although they were not members.

Established following the death of Gustavus Adolphus of Sweden at Lützen, in November 1632, it was directed by Sweden, with France providing financial support. Despite competing priorities and objectives, the League achieved considerable success, before its defeat at Nördlingen in November 1634.

This provided an opportunity for Emperor Ferdinand to negotiate with his Protestant opponents. The Peace of Prague largely ended conflict between members of the Holy Roman Empire, and the League was dissolved. However, fighting in Germany continued until 1648, much of it driven by foreign powers including France, Sweden, the Dutch Republic and Spain.