| Siege of Geldern | |||||||
|---|---|---|---|---|---|---|---|
| Part ofEuropean theater of the Seven Years' War | |||||||
.jpg) Contemporary engraving depicting the siege of Geldern in 1757 | |||||||
| |||||||
| Belligerents | |||||||
 France |  Prussia | ||||||
| Commanders and leaders | |||||||
| Duc d'EstréesComte de Beausobre | Friedrich von Salmuth [de] | ||||||
| Strength | |||||||
| Thousands | 800 | ||||||
| Casualties and losses | |||||||
| Unknown | Unknown | ||||||
Thesiege of Geldern was one of the first military confrontations betweenFrance andPrussia during theSeven Years' War. Surrounded by an advancing French army, the Prussian garrison of Geldern surrendered after a four-monthsiege.
In the wake of theDiplomatic Revolution of 1756 and the subsequentFirst Treaty of Versailles, France agreed to a defensive pact with its new ally,Austria, if either were attacked byGreat Britain orPrussia.[1]
On 29 August 1756,Prussia launched a pre-emptive invasion of the Austrian ally ofSaxony, starting theThird Silesian War, and therefore drawing France into the new conflict.
The invasion led to the signing of theSecond Treaty of Versailles between Austria and France on 1 May 1757. In the treaty, France promised to strengthen its commitment totheir existing alliance by raising an army inFlanders to invade Prussia from the west. However, France had already been assembling troops in Flanders as early as March to invade the British ally ofHanover.[2]
With theFrench invasion of Hanover looming,Frederick II of Prussia ordered for the Prussian fortress ofWesel to be evacuated in early 1757, and its garrison sent to join the assemblingHanoverian Army of Observation, leaving the garrison ofGeldern on the western extremity of the Kingdom of Prussia isolated.
The garrison of Geldern exchanged fire with French hussars on 25 March,[3] and would later fall under a full siege when the French surrounded the town on 14 April.[4]
The Prussians attempted to flood the approaches to the fortifications, but were only partly successful. During the siege, part of the mostly-foreign Prussian garrison mutinied, although this was swiftly dealt with by von Salmuth.[5] The garrison finally surrendered on 23 August and, in recognition of its stubborn defence, was allowed by Beausobre to withdraw to the Prussian stronghold ofMagdeburg unmolested.[6]
Although the siege had delayed part of the French army for several months, its conclusion allowed them to rejoin the rest of French army in the invasion of Hanover. By the time the Prussians reached Magdeburg on 4 October, almost all of the original Geldern garrison had deserted along the way.[7]