Franco-Spanish War (1635–1659)

Background

The Thirty Years' War began in 1618 when the Protestant-dominated Bohemian Estates offered the Crown of Bohemia to Frederick V of the Palatinate, in place of the Catholic Ferdinand II. Most of the Holy Roman Empire remained neutral, and the Bohemian Revolt was quickly suppressed. However, the war expanded when Spanish forces invaded the Palatinate and forced Frederick into exile. The removal of a hereditary prince changed the nature and extent of the war.

As part of a general policy aimed at limiting Habsburg expansion wherever possible, Catholic France supported their largely Protestant opponents. This included backing the Dutch Republic in the Eighty Years' War, as well as funding first Danish, then Swedish intervention in the Thirty Years' War. In 1630, Gustavus Adolphus of Sweden invaded Pomerania, partly to support his Protestant coreligionists, but also to control the Baltic trade, whose tolls provided much of Sweden's income.

Although Swedish intervention continued after Gustavus' death at Lützen in 1632, it caused tensions with Saxony and Brandenburg-Prussia, whose lands were devastated by the plague and famine that accompanied the war. Imperial-Spanish victory at Nördlingen in September 1634 forced the Swedes to abandon southern Germany, and most of their German allies made peace with Ferdinand II at Prague in April 1635.

Rumours of a proposed Austro-Spanish offensive in the Netherlands led Louis XIII of France and Richelieu to decide on direct intervention. In early 1635, Bernard of Saxe-Weimar agreed to provide 16,000 troops for a campaign in Alsace and the Rhineland, while Louis XIII simultaneously signed an anti-Spanish alliance with the Dutch, and the Treaty of Compiègne with Sweden.

Phase I: 1635 to 1648 Treaty of Westphalia

In May, a French army of 27,000 defeated the Spanish at Les Avins, and besieged Leuven on 24 June, where they were joined by Dutch troops. The siege made little progress, and on 4 July the French withdrew across the border having suffered severe losses from disease. Led by Cardinal-Infante Ferdinand of Austria, the Spanish captured Limbourg and Gennep, then besieged Dutch garrisons in the Duchy of Cleves, including Schenkenschanz. The latter was taken by the Spanish on 28 July, and recovered only after a long and costly siege.

The States General of the Netherlands now opposed further large-scale land operations in favour of attacks on Spanish trade. In 1636, Philip switched his focus to recovering territories in the Low Countries, while a Franco-Savoyard offensive in Lombardy was defeated at Tornavento in June. A Spanish incursion into northern France reached as far as Corbie in August, but despite causing panic in Paris, the Cardinal-Infante retreated due to supply problems, and the attempt was not repeated.

As agreed in 1635, the French replaced Swedish garrisons in Alsace with mercenaries supplied by Bernard of Saxe-Weimar. Before his death in 1639, the latter won a series of victories in the Rhineland, notably the capture of Breisach in December 1638. The loss of Alsace meant Spanish troops in Flanders had to be resupplied by sea rather than land, making them vulnerable to the Dutch States Navy, which destroyed a large Spanish supply fleet at the Battle of the Downs in 1639. Although most convoys got through, its loss illustrates the difficulties Spain faced in sustaining its war effort in the Low Countries.

With Spain focused on Europe, the Dutch attacked their colonial possessions, especially those belonging to the Portuguese Empire. Then ruled by Philip IV, his inability to protect these interests caused increasing unrest in Portugal. Damage to the economy and tax increases imposed to pay for the war led to protests throughout Spanish territories, which in 1640 erupted into open revolts in Portugal and Catalonia. In 1641, the Catalan Courts recognised Louis XIII as Count of Barcelona and ruler of the Principality of Catalonia. However, the war turned into a contest between the Franco-Catalan and Spanish elites, with the bulk of then population opposed to both.

Louis XIII died on 14 May 1643, and was succeeded by his five-year-old son, Louis XIV, whose mother, Anne of Austria, took control of the Regency Council that ruled in his name. Five days later, Louis II de Bourbon, Prince of Condé defeated the Spanish Army of Flanders at Rocroi. Victory gave Condé, a Prince du sang and effective ruler of much of eastern France, leverage in his struggle with Queen Anne and Cardinal Mazarin.

Despite a series of defeats in Flanders, including Lens in August 1648, Spain remained in the war, while French successes in Germany at Nördlingen and Zusmarshausen were offset by losses at Tuttlingen and Herbsthausen. In Italy, French-backed Savoyard offensives against Milan achieved little because of lack of resources and the disruption caused by the 1639 to 1642 Piedmontese Civil War. Victory at Orbetello in June 1646, and the recapture of Naples in 1647 left Spain firmly in control of the Italian Peninsula.

The 1648 Peace of Westphalia ended the Thirty Years' War, recognised Dutch independence and ended the drain on Spanish resources. Under the October 1648 Treaty of Münster, France gained strategic locations in Alsace and Lorraine, as well as Pinerolo, which controlled access to Alpine passes in Northern Italy. However, the peace excluded Italy, Imperial territories in the Low Countries and French-occupied Lorraine. This meant that although Emperor Ferdinand and France were formally at peace, it allowed fighting between France and Spain to continue.

Phase II: 1648 to 1659

Philip IV of Spain was forced to declare bankruptcy in 1647, and thereafter focused on retaking Catalonia, while remaining on the defensive elsewhere. Although many of the troops captured at Rocroi soon returned to service, in their absence a significant part of Flanders was overrun, including Dunkirk, a major base for Spanish privateers attacking Dutch and French shipping. However, Spain's position improved when the Dutch war ended in 1648, along with the outbreak of the Fronde in France.

This allowed Spain to retake most of its lost ground in Flanders, including Ypres, but neither side could gain a significant advantage. In 1650, Spanish success in crushing the Neapolitan Revolt was offset by the loss of Barcelona to French-backed Catalan rebels. Mazarin forced Condé into exile in the Spanish Netherlands in 1651, where his immense prestige in territories adjacent to the Spanish possession of Franche-Comté made him a valuable Spanish ally.

During 1652, Spain recaptured both Dunkirk and Barcelona, and although limited combat continued in Roussillon, the front had stabilised along the modern Pyrenees border. However, the cost of doing so forced Philip to declare bankruptcy again, while the end of the Fronde allowed Mazarin to resume attacks on Milan and thus threaten southern Austria. The attempt failed despite support from Savoy, Modena and Portugal. By now, the two antagonists were exhausted, with neither able to establish dominance. From 1654 to 1656, French successes at Arras, Landrecies and Saint-Ghislain were offset by Spanish victories at Pavia and Valenciennes. Under pressure from Pope Alexander VII, Mazarin offered peace terms but refused to accept Philip's insistence Condé be restored to his French titles and lands. Since Philip IV viewed this as a personal obligation to Condé, the war continued.

The loss of Dutch naval support after Westphalia in 1648 was remedied by Mazarin in 1657, when he negotiated the Treaty of Paris (1657) with the Commonwealth of England, then engaged in the Anglo-Spanish War (1654–1660). Under its terms, France withdrew support for the exiled Charles II of England, whose supporters joined the Spanish as a result. After the capture of Dunkirk in June 1658, Philip requested a truce, which Mazarin refused, but Oliver Cromwell's death in September led to political chaos in England. Fighting in northern Italy ended when Savoy and Modena agreed to a truce with Spanish commander Caracena.

Treaty of the Pyrenees and marriage contract

On 8 May 1659, France and Spain began negotiating terms; Cromwell's death in September 1658 weakened England, which was allowed to observe but excluded from the talks. Although the Anglo-Spanish War was suspended after the 1660 restoration of Charles II, it did not formally end until the Treaty of Madrid (1667).

Under the Treaty of the Pyrenees, signed on 5 November 1659, France gained Artois and Hainaut along its border with the Spanish Netherlands, as well as Roussillon. These were more significant than often assumed; in combination with the 1648 Treaty of Münster, France strengthened its borders in the east and south-west, while in 1662, Charles II sold Dunkirk to France. Acquisition of Roussillon established the Franco-Spanish border along the Pyrenees, but divided the historic Principality of Catalonia, an event still commemorated each year by French Catalan-speakers in Perpignan. In addition to these territorial loses, Spain was forced to recognize and confirm all of the French territorial gains at the Peace of Westphalia.

France withdrew support from Afonso VI of Portugal, while Louis XIV renounced his claim to be Count of Barcelona, and king of Catalonia. Condé regained his possessions and titles, as did many of his followers, such as the Comte de Montal, but his political power was broken, and he did not hold military command again until 1667.

An integral part of the peace negotiations was the marriage contract between Louis and Maria Theresa. He would subsequently use the terms to justify the 1666 to 1667 War of Devolution, and they formed the basis of French claims for the next 50 years. The marriage was more significant than intended, since it was agreed shortly after Philip's second wife, Mariana of Austria, gave birth to a second son, both of whom died young. Philip died in 1665, leaving his four-year-old son Charles as king, once described as "always on the verge of death, but repeatedly baffling Christendom by continuing to live."

Financial and military impact

Taking on the Spanish Empire, then the strongest military power in Europe, required French forces of unprecedented size and an associated expansion of the taxation and supply base needed to support them. To meet these needs, official estimates for the army expanded from 39,000 in 1630 to around 150,000 shortly before the declaration of war in May 1635. However, in the early stages of the war, French logistics could not yet feed and support such numbers. Within a month of entering the Spanish Netherlands, nearly half the 27,000 men who took part had either fallen ill, or deserted due to lack of pay. Although this improved as time progressed, throughout the war both sides struggled to conduct offensives outside their own territories, as with the 1636 Spanish invasion of northern France.

Including those supplied by Bernard of Saxe-Weimar and paid by France, between 1635 and 1642 official troop levels averaged 150,000 to 160,000, with a peak of 211,000 in 1639. These should be treated with caution, since officers were paid for the numbers they reported, rather than those actually present, while up to another 10% was absent due to sickness, although most recovered. Parrott estimates variances between "Reported" and "Actual" averaged up to 35% for the French and 50% for the Spanish, although John A. Lynn suggests 60%.

Throughout the war, military strategy and objectives were often secondary to finding supplies, especially given the primitive infrastructure then available. It was not until the 1660s that Louvois created systems which allowed France to sustain an army of nearly 200,000 men for extended periods, and crucially ensure co-ordinated strategy between different fronts. At the start of the war, the more experienced Spanish were better equipped while their resources made it easier to replace losses. The French sought to negate those advantages by fighting on multiple fronts and supporting anti-Spanish forces in Catalonia, Naples and Portugal. Loss of Dutch naval support after 1648 severely impacted France's ability to challenge the Spanish at sea, until replaced with the English alliance in 1657.

At its peak in 1632, the Spanish army contained around 300,000 regulars and 500,000 local militia, who were in general suitable only for garrison duty. In 1632, only 30% of the Castilian militia possessed firearms, and although this briefly improved, by 1659 this had fallen to less than 13% of the 465,000 listed in their registers. Many were recruited from Castile and Aragon, with some estimates suggesting 288,000 losses during the war, including non-combat related causes. In contrast, French losses were around 300,000 in combat and 200,000 out of combat.

During the 1630s, the Spanish state increasingly relied on its Italian territories for recruits and money, Milan alone providing around 4,000 recruits and 6 million scudi per year. In addition to maintaining its own forces, from 1630 to 1643 Naples supplied an average of 10,000 recruits a year, an annual subsidy to Madrid of one million ducats, and paid a third of Milan's government expenditures. As a result, its public debt quintupled and by 1648 interest payments constituted 57% of revenue, while taxes tripled between 1618 and 1688, crushing the southern Italian economy. In October 1647, revolts in Sicily and Naples were quickly suppressed, but they exposed the weakness of Spanish rule in Italy and alienation of the local elites from Madrid. In 1650, the governor of Milan claimed only Parma could be relied upon.

Aftermath and historical assessment

Although relatively minor in extent, French territorial gains were strategically significant in terms of securing their southwest and north-east borders. Since traditional historiography portrayed the conflict as starting the process whereby France gradually replaced Spain as the predominant European power, it was often presented as ending in favour of France, but modern analysis suggests a more balanced outcome. Overall, most historians view the conflict as militarily indecisive, with both sides stuck in a stalemate from 1637 to 1659.

The treaty has also been seen as a major foreign policy success for Mazarin, although the terms he ultimately accepted were less favourable than proposed in the 1647 negotiations. One view is Spain escaped surprisingly lightly, considering its position immediately prior to the end of the war.

In territorial terms, Spain remained the predominant European power for decades, but its economic and military power suffered an abrupt decline after 1659. Although Madrid played an important role in the anti-French coalitions that fought Louis XIV in the Franco-Dutch War and the Nine Years' War, it was increasingly unable to defend territories outside Peninsular Spain without foreign support. The Spanish Netherlands, many of whose fortresses were in disrepair and their troops poorly supplied, became particularly vulnerable to French attack.