Key Facts
- Duration
- 3 May – 23 August 1645 (nearly 4 months)
- Defender force size
- ~1,500 (500 soldiers + ~1,000 residents)
- Attacking force size
- ~28,000 Swedish soldiers
- Swedish commander
- General Lennart Torstensson
- Habsburg commander
- Jean-Louis Raduit de Souches
Strategic Narrative Overview
Beginning on 3 May 1645, Torstensson's force of approximately 28,000 besieged the city. The garrison, comprising only around 500 soldiers supplemented by roughly 1,000 armed townspeople, was commanded by Jean-Louis Raduit de Souches. Despite the extreme disparity in numbers, the defenders held every assault for nearly four months, tying down a large Swedish army that could not be employed elsewhere.
01 / The Origins
By the mid-1640s the Thirty Years' War had entered its final phase, with Sweden pressing deep into Habsburg-controlled Central Europe. Swedish forces under General Lennart Torstensson swept through Moravia, having already conducted one earlier siege of Brno. Control of the region's urban centers was critical to Swedish strategic ambitions and to pressuring the Habsburg emperor toward a favorable peace.
03 / The Outcome
The Swedes lifted the siege on 23 August 1645, withdrawing without taking the city. The successful defense launched Raduit de Souches on a distinguished Habsburg military career. The siege's outcome contributed to Brno supplanting the Swedish-occupied Olomouc as the principal city of Moravia, a status Brno would retain long after the war ended with the Peace of Westphalia in 1648.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Lennart Torstensson.
Side B
1 belligerent
Jean-Louis Raduit de Souches.
Kinetic Engagement Axis
Scroll horizontally to view full axis. Events plotted relatively.