22,000 15,370–18,000[2] The Battle of Zusmarshausen was fought on 17 May 1648 between Bavarian-Imperial forces under von Holzappel and an allied Franco-Swedish army under the command of Carl Gustaf Wrangel and Turenne in the modern Augsburg district of Bavaria, Germany.

To cover the retreat he detached a force of 2000 Croatian cavalry under Raimondo Montecuccoli to perform a rearguard action at a bridge over the Zusam river, in the village of Zusmarshausen.

This time, however, a group of French cavalry managed to work their way round the southern side of Montecuccoli's position, threatening to cut him off from the rest of the Imperial-Bavarian army.

[5] Montecuccoli managed to extricate his surviving men from Herpfenried around midday, and at 2 PM he rejoined Gronsfeld and the rest of the army, which had assumed a defensive position on the east bank of the Schmutter.

Later that afternoon the French vanguard appeared and made a couple of probing attacks across the river, but they lacked the strength to mount a serious assault (most of the Franco-Swedish army was still strung out along the road from Ulm) and night fell before these forces could become available.

The losses of the Imperial-Bavarian army were 1,582 dead or wounded, 315 prisoners, 6 field guns, parts of the baggage and the fallen commander von Holzappel but the bulk of the force escaped.

Their opponents' retreat allowed Wrangel and Turenne to advance across southern Bavaria and to plunder the area between Lech and Isar where the Swedes took Freising and Landshut.

[8] Despite the army being shrunk by desertions to at one point only 10,000 men, Hunolstein prevented Wrangel from crossing the fortified and heavily swollen river Inn in southern Bavaria and reorganized the defense together with Piccolomini.