HistoryData
war1631

Protestants’ first major victory of the Thirty Years War in 1631

September 17, 1631

The first major Protestant victory of the Thirty Years' War, enabling Swedish expansion into southern Germany.

Quick Facts

Year
1631
Category
war

Key Facts

Date
17 September 1631
Swedish-Saxon force size
~40,150 troops
Imperial-Catholic League force
~31,400 troops
Swedish intervention began
June 1630, landing in Pomerania
Swedish force at landing
nearly 18,000 troops

By the Numbers

17
Date
40,150
Swedish-Saxon force size
31,400
Imperial-Catholic League force
1,630
Swedish intervention began

Location

Map of Breitenfeld, Leipzig, GermanyMap of Breitenfeld, Leipzig, GermanyBreitenfeld, Leipzig, Germany

Cause → Event → Consequence

Cause

Swedish intervention in the Thirty Years' War began in June 1630, when Gustavus Adolphus landed in Pomerania with around 18,000 troops, financed by French subsidies. In early 1631, Imperial commander Tilly invaded Saxony after Elector John George I formed an alliance with Sweden, prompting the combined Swedish-Saxon army to march on Leipzig.

Event

On 17 September 1631, a Swedish-Saxon army of roughly 40,150 under Gustavus Adolphus and John George I engaged Tilly's Imperial-Catholic League force of 31,400 near Breitenfeld. The Saxon flank was routed early, but the Swedes regrouped, launched sustained counterattacks, and forced Tilly to retreat with substantial losses.

Consequence

The defeat of Tilly's Imperial-Catholic League army gave Protestants their first significant battlefield success of the war. The victory opened southern Germany to a Swedish campaign and fundamentally shifted the strategic balance, demonstrating the effectiveness of Swedish military tactics against the previously dominant Imperial forces.

Belligerents & Mobilization Analysis

Side A

2 belligerents

SwedenElectorate of Saxony
Key Commanders

Gustavus Adolphus, John George I, Elector of Saxony.

Side B

2 belligerents

Holy Roman Empire (Imperial Army)Catholic League
Key Commanders

Johann Tserclaes, Count of Tilly.

Outcome
Decisive Swedish-Saxon victory; Tilly forced to retreat with substantial losses

Timeline Context

Timeline around 16311631162816291630163216331634Franco-Moroccan TreatyMilitary agreement between France and Sweden1631 secret pact of mutual assistance between Electorat of Bavaria and France1631 naval battle of the Dutch invasions of Brazilbattle-of-breitenfeld-1631