The Franco-Spanish War, from May 1635 to November 1659, was fought between France and Spain, each supported by various allies at different points. It consists of two distinct phases, the first from May 1635 to October 1648, which is considered a related conflict of the Thirty Years' War, the second continued until the Treaty of the Pyrenees in 1659.
Major areas of conflict included northern Italy, the Spanish Netherlands and the Rhineland. France supported revolts against Spanish rule in Portugal (1640–1668), Catalonia (1640–1653) and Naples (1647), while Spain backed French rebels in the 1647 to 1653 "Fronde". Both also backed opposing sides in the 1639 to 1642 Piedmontese Civil War.
In the first phase of the Thirty Years' War, France provided support for both the Dutch Republic and Sweden against Spain and Austria, but prior to May 1635 had avoided direct participation. At this point, France declared war on Spain, then shortly afterwards separately entered the 30 Years War against Austria. After the latter ended in 1648, fighting continued between Spain and France, with neither able to achieve decisive victory. France made some gains in Flanders and the Pyrenees, but by 1658 both sides were financially exhausted and made peace in November 1659.
While French territorial gains were relatively modest, they strengthened the kingdom's frontiers, while the marriage of Louis XIV to Maria Theresa of Spain enhanced Bourbon dynastic claims. Traditionally, the Treaty of the Pyrenees has been viewed as marking the end of Spain's position as the predominant European power. More recent assessments have been more cautious, noting that the conflict itself remained militarily indecisive and that the Spanish Empire retained its vast overseas territories, thus remaining a major power, while some historians argue that Spain escaped with comparatively light terms.
Strategic overview
From 1618 to 1648, Europe was dominated by the Thirty Years' War, another outlet in the long-running contest between France, and its Habsburg rivals in Spain and the Holy Roman Empire. In its first stages, France avoided direct involvement, instead financing Habsburg opponents such as the Dutch Republic, and backing Swedish intervention in the Thirty Years' War. When fighting seemed likely to end in May 1635, France declared war on Spain and Emperor Ferdinand. From 1640 onwards, it also supported insurgencies in Catalonia, Portugal, and Naples.
For their part, the Habsburgs backed a series of Huguenot rebellions and conspiracies by feudal lords who resented their loss of power under Cardinal Richelieu and his successor, Cardinal Mazarin. They included those led by Montmorency in 1632, the Princes des Paix plot by Louis, Count of Soissons in 1641, and Cinq-Mars in 1642. Spain also backed anti-government rebels in the 1648–1653 French civil war known as the Fronde.
Wider co-operation between the Spanish and Austrian Habsburgs was limited since their objectives did not always align. Spain was a global maritime power, while Austria was primarily focused on the Holy Roman Empire. Although the Habsburgs had been Holy Roman Emperors since 1440, their control over the empire was weakened by the 1555 Peace of Augsburg, which continued in the period leading up to 1620. Reversing the trend was a major Habsburg objective during the Thirty Years' War, but failure was acknowledged by the 1648 Peace of Westphalia.
France faced the same issue of diverging objectives with its allies. The war coincided with the period of economic supremacy known as the Dutch Golden Age, and by 1640, many Dutch statesmen viewed French ambitions in the Spanish Netherlands as a threat. Unlike France, Swedish war aims were restricted to Germany, and in 1641, the Swedes considered a separate peace with Ferdinand II's son, Ferdinand III.
From the beginning of the Dutch Revolt in 1569, Italy, especially the Kingdom of Naples, was the primary source of recruits and money for the Army of Flanders. As a result, much of the fighting focused on the Spanish Road, a land supply route connecting Spanish possessions in Italy with Flanders but also passing through areas considered vital to French security, like Alsace. The independent Duchy of Savoy and Spanish-held Duchy of Milan were strategically important to the Road but also provided access to the vulnerable southern borders of France and Habsburg territories in Austria. Richelieu aimed to end Spanish dominance in those areas, an objective largely achieved at his death in 1642.
Until the advent of railways in the 19th century, water was the primary means of bulk transportation, and campaigns focused on control of rivers and ports. Armies relied on foraging, while the feeding of the draught animals essential for transport and cavalry restricted campaigning in the winter. By the 1630s, the countryside had been devastated by years of constant warfare, which limited the size of the armies and their ability to conduct operations. Sickness killed far more soldiers than combat. The French army that invaded Flanders in May 1635 had been reduced by desertion and disease from 27,000 to under 17,000 by early July.
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).