Siege of Saint-Omer

Siege of Saint-Omer
Part of the Thirty Years' War and the Franco-Spanish War (1635-1659)
The relief of Saint-Omer by Peter Snayers. Oil on canvas. Museo del Prado, Madrid.
Date 24 May – 16 July 1638 Location Saint-Omer and its outskirts, Spanish Netherlands (present-day France) 50°44′46″N 2°15′42″E / 50.7461°N 2.2617°E / 50.7461; 2.2617 Result Imperial-Spanish victory
Belligerents
Spain  Holy Roman Empire	France
Commanders and leaders
Cardinal-Infante Ferdinand Prince of Carignano Ottavio Piccolomini	Maréchal de Châtillon Duc de La Force
Strength
20,000[1]	29,000[2][3] 10,000 infantry 3,000 cavalry 16,000 infantry and cavalry
Casualties and losses
At least 34 dead or wounded[4][5]	4,000 dead or wounded[1] 1,220 captured[6]

The siege of Saint-Omer (24 May – 16 July 1638) was a siege in the Thirty Years' War in which a French army under Gaspard III de Coligny, Maréchal de Châtillon, laid siege to the Flemish city of Saint-Omer, defended by a small garrison in command of Lancelot II Schetz, count of Grobbendonck. Despite several initial successes in the capture of the minor forts around Saint-Omer, on the night of 8/9 June a Spanish relief army under Thomas Francis, Prince of Carignano, surprised Châtillon's troops and established a small fort in the middle of the French lines.^[2] An entire army corps under Maréchal de La Force was ordered to move towards Saint-Omer to support Châtillon siege, but on 12 July a further Imperial-Spanish force commanded by Ottavio Piccolomini entered Saint-Omer, resolving the French marshals to withdraw.^[2]