The Spanish–Portuguese War (1762–1763) or Fantastic War (; ; ; ) was fought as part of the Seven Years' War. The first and main theatre of the war was an invasion of Portugal by Spain in alliance with France against the Anglo-Portuguese Alliance, which ended after three disastrous invasions. The second theatre was a Spanish invasion of Portuguese colonies in South America. Though tactically successful for the Spanish in the strategically important area on and near the River Plate, their gains there were largely given up in the peace negotiations, resulting in a strategic success for the Portuguese in South America.
Because no major battles were fought in the Portuguese segment of the war, even though there were numerous movements of troops and heavy losses among the Franco-Spanish invaders, this theatre of the Seven Years' War is known in Portuguese historiography as the Fantastic War (Portuguese and Spanish: Guerra Fantástica) in the sense of phantom war, due to the successful Portuguese strategy of starving the invading Franco-Spanish army of supplies while avoiding or minimising pitched battles.
The war ended along with the Seven Years' War in the 1763 Treaty of Paris.
Background When the Seven Years' War between France and Great Britain started in 1754, Spain and Portugal remained neutral, their differences in South America having been settled by the Treaty of Madrid of 1750. Ricardo Wall, prime minister to King Ferdinand VI of Spain, was opposed to the pro-French party at court who wanted to enter the war on the side of France.
All this changed when Ferdinand died in 1759 and was succeeded by his younger half-brother Charles III. The more ambitious Charles was motivated to preserve Spain's position as a leading European and colonial power. By 1761 France looked to be losing the war against Great Britain. Fearing a British victory over France, Charles signed the Family Compact with France (both countries were ruled by branches of the House of Bourbon) in August, and claimed compensation for attacks by English privateers in Spanish waters. This brought war with Great Britain in January 1762. Portugal had been weakened by the disastrous 1755 Lisbon earthquake, leading Prime Minister Sebastião José de Carvalho e Melo, Marquis of Pombal, to direct all efforts towards the reconstruction of the country and neglected the armed forces, in which he had little interest. A new treaty between Spain and Portugal, the Treaty of El Pardo of 1761, rendered the Treaty of Madrid null and void.
At the urging of the French government, Spain agreed to attack Portugal, which had been neutral, but served as an important economic ally of Great Britain. The invasion was not intended to conquer Portugal but to create a new front that would draw away British forces, now directed against France.
The third Franco-Spanish invasion of Portugal in Europe (main theatre of the war, which absorbed much of the Spanish war effort),"Preparations the Spanish Government made for war after signing the compact with France focused more on Portugal than the colonies. (...)", In Greentree, David – A Far-Flung Gamble – Havana 1762, Osprey Publishing, Oxford, 2010, p. 30."This operation was without doubt the greatest mobilisation of troops on mainland Spain throughout the whole eighteenth century, and the figures themselves bear witness to the government's interest in the operation...and meant leaving the rest of mainland Spain largely unguarded...by way of comparison, the Battle of Almansa of 1707...involved a Spanish-French army of over 25,000 men...while the famous attack on Algiers in 1775 involved a mobilisation of little more than 19,000 infantry and cavalry men..." in Enciso, Agustín González (Spanish) – "Mobilising Resources for War: Britain and Spain at Work During the Early Modern Period", Eunsa, Ediciones Universidad de Navarra, S.A., Spain, 2006, p. 159, . on 5 May 1762, was followed by a Spanish invasion of Portuguese territories in South America (a secondary theatre of the war). While the first ended in humiliating defeat,"In 1762, England declares war on Spain; helps Portugal to defeat the Spanish invasion of that kingdom and captures Havana and Manila." In Singleton, Esther – The World's great events: an indexed history of the world from earliest times to the present day , Vol. V, P. F. Collier, New York, 1916, p. 1635."After the Seven Years' War, relations between them in 1763 were extremely bitter (...). Portugal could not at once forget the sudden invasion of her territory, as that of an English ally, by an army from Spain, when that Power decided to enter the recent international conflict, while Spain smarted from a sense of humiliation at the remembrance of the failure of that campaign." In Holmes, Vera Brown- Studies in the History of Spain in the Second Half of the Eighteenth Century, Vol. 15 and 16, The Dept. of history of Smith college, 1929, USA, p. 65. the second represented a stalemate: Portuguese victory in remote areas in northern and western Brazil; Spanish victory in the strategically sensitive area on and near the River Plate.
Peninsular theatre
During the war, a Franco-Spanish army of about 42,000 men, first led by Nicolás de Carvajal, Marquis of Sarria and then by Pedro Pablo Abarca de Bolea, 10th Count of Aranda, invaded Portugal in 1762, in three different regions at three different times: provinces of Trás-os-Montes (May–June 1762), province of Beira (July–November 1762) and Alentejo (November 1762). They were faced by ferocious popular resistance and, from the middle of the second invasion onwards, by an Anglo-Portuguese army of nearly 15,000 men commanded by William, Count of Schaumburg-Lippe.
In the first invasion, the Spanish – whose final goal was Porto, the second city of the kingdom – occupied without opposition several undefended towns and ruined fortresses of the Trás-os-Montes Province; there were neither regular soldiers nor gunpowder in the entire province, except in the fortress of Miranda do Douro. However, guerrillas exploited the mountainous nature of the province to cut off the invaders' supply and communication lines with Spain as well as to inflict heavy losses."...the militia of Portuguese peasants, whose intervention, coupled with the inaccessibility of the terrain, caused the failure of the Spanish invasion by the North [ Portugal] in 1762...", see Arenas, Mar García – Los Proyectos del General Dumouriez Sobre la Invasión de Portugal in El Equilibrio de los Imperios: de Utrecht a Trafalgar, Actas de la VIII Reunión Científica de la Fundación Española de Historia Moderna (Madrid, 2–4 de Junio de 2004), vol. II, Fundación Española de Historia Moderna, 2005, p. 548. The Portuguese abandoned their villages, inducing famine among the Spaniards, who launched two offensives towards Porto: the first was defeated by the militia and peasants at the Battle of Douro and the second was beaten off at the mountains of Montalegre. This failure and the arrival of Portuguese reinforcements (including regular troops) forced the now diminished Spanish army to retreat into Spain, abandoning all their conquests (except Chaves). After this defeat, the Franco-Spanish commander, Sarria, was replaced by the Count of Aranda."after the failed attempt of General Sarria, Charles III of Spain gave the command of the campaign to a younger and proud military, the count of Aranda...", In Huarte, Eulogio Zudaire- Don Agustín de Jáuregui y Aldecoa, Vol. I, Institución Príncipe de Viana, 1978, p. 45
During this first invasion of Portugal, the total Spanish casualties, according to a contemporaneous French source, Charles François Dumouriez, were 10,000 men:"This province [of Trás-os Montes] is not worth an attack in a war between Spain and Portugal; it is even dangerous for the Spaniards to penetrate into it, as they found to their cost in the late war; 40,000 men advanced to Chaves, Bragança and Miranda...and about a fourth of their number died there..." In Dumouriez, Charles – An Account of Portugal, as it Appeared in 1766 to Dumouriez, Lausanne (1775), and London (1797), p. 20. prisoners, deserters or deaths by hunger, guerrilla ambushes and disease (8,000 according to modern Spanish military historian José Luis Terrón Ponce).Ponce, José Luis Terrón – , Institut Menorquí d´Estudis, Mahón, 2011, La campaña de Portugal en 1762, pp.11–21, p. 13. At the request of Portugal, one British force of 7,107 soldiers and officers landed in Lisbon, deeply reorganizing the Portuguese army (7 to 8,000 regular soldiers). The supreme command of the allied army (from 14 to 15,000 men) was delivered to one of the best soldiers of his time:"Under Count Von Lippe´s administration, the Portuguese army became an efficient and well-uniformed war machine and the strong Prussian influence of its mentor contributed to repulsing the expansionist attempts of the Spanish Crown." In Moreira, Maria and Veludo, Sérgio- Portuguese Studies Review, Volume 16, nr. 2, Baywolf Press, 2008, p. 83, ISSN 1057-1515. the Count of Lippe.
In the beginning of the second invasion (province of Lower Beira, July–November 1762), the Franco-Spaniards captured several poorly equipped Portuguese fortresses and towns, including Almeida. However, the Anglo-Portuguese army defeated a Spanish corps which was preparing another invasion through the province of Alentejo at the Battle of Valencia de Alcántara, and foiled the Spanish attempt to cross the river Tagus, defeating them at Vila Velha.
The allied army eventually stopped the Bourbon army's march toward Lisbon in the mountains near Abrantes (which by its position dominated the country) and used a scorched earth strategy – in cooperation with the rural population – to starve the invaders: peasants abandoned their villages, destroying or taking with them all the food, while the guerrillas attacked their logistic lines."... the main central attack on Portugal [second invasion] failed utterly...partly through the skilful measures of the Count of Lippe, who had been placed in charge of the Portuguese army, and strengthened by 7,000 British troops, partly through the bold partisan enterprises carried out against their line of communications by General John Burgoyne [and the guerrillas]...But mainly the invasion failed through the absolute lack of munitions and food; the Portuguese – as was their wont – had swept the countryside clean [a deadly scorched earth strategy], (...). After starving for some weeks in a roadless wilderness, the Spanish army retired into Estremadura [Spain] in a sad state. The next spring, Charles III sued for peace. " in Journal of the Royal United Service Institution, Whitehall Yard, Vol. 63, W. Mitchell, United Kingdom, 1918, p. 196. The invaders had to choose between stay and starve or withdraw.