Crossing of the Somme The Crossing of the Somme took place on 5 August 1636 during the Thirty Years ' War and the Franco - Spanish War when units of the Spanish Army of Flanders , the Imperial Army and the Duchy of Lorraine under Thomas Francis , Prince of Carignano , lieutenant of the Cardinal - Infante Ferdinand of Austria , crossed the Somme river near Bray - sur - Somme during its offensive in French territory . Despite the fierce resistance of the French army led by Louis de Bourbon , Count of Soissons , the Spanish troops successfully crossed the river and drove off the French troops along the Oise river , proceeding over the following weeks to invest the important fortress of Corbie , located two leagues of Amiens , which caused a spread of panic among the population of Paris . Background . Shortly after France declared the war on Spain in May 1635 , a French army under the Marshals of France Urbain de Maillé - Brézé and Gaspard III de Coligny , allied with the Dutch States Army , invaded the Spanish Netherlands from two sides and threatened Brussels before investing Leuven . The siege ended in a costly failure because of bad logistics and organization , and as the French army was decimated by the plague . The Cardinal - Infante Ferdinand , governor of the Spanish Netherlands , counterattacked and expelled the invaders , concentrating his resources against the Dutch over the following months . The recapture by the statholder Frederick Henry of Orange of the key fortress of Schenkenschans did not discouraged the Spanish , and the Count - Duke of Olivares continued determined to concentrate the war effort against the Dutch . After suffer further defeats against the armies of the Duke Charles of Lorraine and the Imperial generalissimo Matthias Gallas in the Rhine , Alsace and Lorraine , the French armies remained focused in the defense and reconquest of strategic places in these territories . The conquest of the Franche - Comté , entrusted to Henri de Bourbon , Prince de Condé and Charles de La Porte de La Meilleraye , soon became an absolute priority to the Cardinal Richelieu . The Holy Roman Emperor , Ferdinand II , whose position in Germany had strengthened since the Peace of Prague , meanwhile , projected an invasion of the eastern France under Matthias Gallas , but as logistical and financial problems diminished his force , he proposed a joint invasion to the Cardinal - Infante . Philip IV of Spain and Olivares rapidly agreed . A lightly equipped army ranging from 10 , 000 – 12 , 000 infantry and 13 , 000 cavalry soldiers to 18 , 000 soldiers of both types , including an imperialist contingent under Ottavio Piccolomini was gathered at Mons during June . On 4 July the Cardinal - Infante crossed the frontier via Avesnes and took the fortresses of Le Catelet and La Capelle . Though having large garrisons , La Capelle surrendered after only four days of siege and Le Catelet , one of the strongest fortresses of France , after three days thanks to the exploding shells used by the Spanish army , a recent innovation yet unfamiliar to the French . The alarming advance of the Cardinal - Infante forced Louis XIII to return to Paris from Fontainebleau . By then Ferdinand was in Cambrai and had left the command of his army to the Prince Thomas Francis of Carignano , the commander of the Army of Flanders . Battle . The Prince of Carignano took over the army and headed to Saint Quentin with the aim of continue the invasion and attract Louis de Bourbon , Count of Soissons , who was in Picardie in command of a force of 14 , 000 soldiers , and his army to the town . Having arrived at the fields in front of Saint Quentin , the Prince changed the route of the army and advanced towards the Somme river . The Cardinal Infante sent to him don Esteban de Gamarra , a gentleman in his confidence , to transmit the order to cross the Somme at the village Bray - sur - Somme or at an easier place even if the French armies were guarding the riverside . Pontoons and boats were dispatched from Cambrai for this purpose . The Prince put on alert his Maestres de Campo and Colonel s and set route to Bray . On 4 August his troops occupied a small island in middle of the river and soon a skirmish began with the French troops on the other riverside . The Count of Soissons , who were stationed with his troops on a nearby hill , believed that the Spanish were attempting to cross the river in that place and detached its battalion s and squadron s near the riverside to reject every attempt . < ref name = " Michaud / Puojuolat 254 " > Michaud / Poujoulat , p . 254 < / ref > The Marquis of Fontenay , who led these troops , set fire to the village and entrenched his soldiers in a series of forts built in the riverside . The skirmish continued a long time with artillery and musketry fire . According to the French , only 20 of his soldiers were killed , among them the Comte de Matha , captain of a company of the Régiment des Gardes . The Prince ordered his Tercios of Spaniards march to the village of Cerisy , located a league south of Bray , and cross there the river . A pontoon bridge was promptly tended from one bank to the opposite , and large amounts of s previously prepared were spread on the marshy land to facilitate the crossing of the soldiers . Only the Régiment de Piedmont was in that place to confront the Spaniards . These formed in squadron at the riverside and became involved in a stubborn fight that lasted for three hours . The Régiment de Piedmont , reinforced by a company of the Régiment des Gardes , tried to expel them from the pontoons and the road of faggots with great fierceness , but thanks to the presence of the Prince , who took the command of the attack , the Spaniards managed to cross the river and drove off the Régiment de Piemont from the riverside . The Maestro de Campo Alonso Pérez de Vivero y Menchaca , Count of Fuensaldaña , put then his soldiers to work in the digging of trench es to cover them from a possible counterattack . The Spanish artillery and some musketeer s riddled the forest where the Régiment de Piedmont had sought coverage and forced the few surviving troops to retreat leaving behind about 300 corpses . The Prince lost that day around 35 soldiers killed and 50 wounded . The French losses could have been higher if the Spanish cavalry had crossed the river on time to pursuit them , but this did not happened and Soissons was able to withdraw his troops in good order . Aftermath . The Prince of Carignano , searching the destruction of the retreating French army , dispatched Ottavio Piccolomini in command of his cavalry and Johann von Werth with the Spanish cavalry behind the Count of Soissons , who was forced to pass the Oise river . The harassment of the German and Spanish cavalry diminished the strength of the French army , finding the Spanish - Imerial troops abandoned corpses and weapons at his advance . Piccolomini ' s persecution of the retreating French army lead him to Roye , which he captured and from where he reached Compiègne and advanced further into French territory , which caused consternation in Paris . Meanwhile , Soissons retreated to Noyon pursued by Johann von Werth . The Bavarian general destroyed 5 French cavalry regiments near the town , but he had not enough forced to attempt its capture . On 7 Agusut the Prince of Carignano , by orders of the Cardinal - Infante , invested the vital fortress of Corbie , which surrendered to him a week later . The following day Louis XIII wrote to the Prince of Condé ordering him to abandon the siege of Dôle and to withdraw from the Franche - Comté to help to defend Paris . At the French court it was believed that after Corbie the Spanish would advance further into France . Piccolomini , who was wishing of do so , tried to persuade the Cardinal - Infante , but this considered that more ambitious operations could risk his army and was resolved to retreat . He was back in Cambrai in early September , before Matthias Gallas ' invasion of France had begun , and the French armies regained most of the lost ground over the following months .