Battle of Fuentes de Oñoro In the Battle of Fuentes de Oñoro ( 3 – 6 May 1811 ) , the British - Portuguese Army under Viscount Wellington checked an attempt by the French Army of Portugal under Marshal André Masséna to relieve the besieged city of Almeida . Background . In 1810 , Masséna had followed the British - Portuguese back to Lisbon before arriving at the Lines of Torres Vedras . He was determined against storming this extensive double line of interlocking fortifications . After starving outside Lisbon through a miserable winter , the French withdrew to the Spanish border with the British - Portuguese army in pursuit . After Portugal was secured , Wellington set about re - taking the fortified frontier cities of Almeida , Badajoz and Ciudad Rodrigo . Whilst Wellington besieged Almeida , Masséna reformed his battered army and marched to relieve the French garrison in the city . Wellington chose to check the relief attempt at the small village of Fuentes de Oñoro . Wellington left his line of retreat exposed to cover all routes to Almeida : he felt this risk was justified because the French would not have more than a few days supplies whereas he had more than that . The British and Portuguese army had 34 , 000 infantry , 1 , 850 cavalry , and 48 guns . The French had 42 , 000 infantry , 4 , 500 cavalry and 38 guns . Organization . The French Army of Portugal . Masséna ' s army was organised into four corps and a cavalry reserve . Louis Henri Loison ' s VI Corps had three divisions , led by Jean Gabriel Marchand , Julien Augustin Joseph Mermet , and Claude François Ferey . In Jean Andoche Junot ' s VIII Corps , only Jean Baptiste Solignac ' s division was present . Jean - Baptiste Drouet ' s IX Corps included the divisions of Nicolas François Conroux and Michel Marie Claparède . Louis Pierre , Count Montbrun headed the cavalry reserve . Jean Reynier ' s II Corps hovered off to the northeast threatening Almeida with its two divisions under Pierre Hugues Victoire Merle and Étienne Heudelet de Bierre . An 800 - men cavalry force , comprising squadrons of the " élite " Imperial Guard " Grenadiers à Cheval " and " Empress Dragoons " was also present at the battle under the command of Marshal Jean - Baptiste Bessières . The reinforcements that Bessières brought were almost symbolic , despite the fact Masséna had requested that he bring the entirety of his Army Corps into battle . The British - Portuguese army . Wellington commanded six infantry divisions , Charles Ashworth ' s independent Portuguese brigade and three cavalry brigades . Brent Spencer commanded the 1st Division , Thomas Picton the 3rd , William Houston the 7th and Robert Craufurd the Light Division . Stapleton Cotton commanded John Slade ' s and Frederick von Arentschildt ' s brigades of cavalry . Edward Howorth supervised four British ( Ross RHA , Bull RHA , Lawson , Thompson ) and four Portuguese ( Arentschildt ( 2 ) , Da Cunha , Rozierres ) 6 - gun batteries . William Erskine ( 5th Division ) , Alexander Campbell ( 6th Division ) and 300 Portuguese cavalry under Count Barbacena were detached , facing the French II Corps . Battle . On 3 May , Masséna launched a frontal assault against the British - Portuguese pickets holding the barricaded village , while bombarding the British - Portuguese on the heights east of the village with heavy artillery . The fight in the center of the villiage lasted all that day , with French soldiers of Ferey ' s and Marchand ' s divisions clashing with the British redcoats of the 1st and 3rd Divisions . At first , the British - Portuguese were driven back under immense pressure , but a charge that included men of the 71st Highland Light Infantry reclaimed the streets and buildings lost earlier in the day . As the sun sank , the French withdrew and the village remained in British hands , with the former suffering 650 casualties against only 250 for the British . 4 May saw little combat . Both sides recovered from the ferocity of the previous day of fighting and reconsidered their options and battle plans . A French reconnaissance revealed that Wellington ' s right flank was weakly held by a unit of partisans near the hamlet of Poco Velho . Action began again at dawn on 5 May . Wellington had left the 7th Division exposed on his right flank . Masséna launched a heavy attack on the weak British - Portuguese flank , led by Montbrun ' s dragoons and supported by the infantry divisions of Marchand , Mermet and Solignac . Right away , two 7th Division battalions were roughed up by French light cavalry . This compelled Wellington to send reinforcements to save the 7th Division from annihilation . This was only achieved by the efforts of the Light Division and the British and King ' s German Legion cavalry . On the threatened British - Portuguese right flank , the elite Light Division , well supported by cavalry and artillery , made a textbook fighting withdrawal . For trifling casualties , they covered the retreat of the 7th Division and fell back into a stronger position selected by Wellington . During the retreat , whenever French artillery ventured too close , the British cavalry charged or feinted a charge . This allowed the infantry time to retreat out of range . If the French horsemen pressed the outnumbered British cavalry back , the British - Portuguese infantry formed square and their volleys drove off the French . Montbrun then requested help from the Imperial Guard cavalry , which were present but had not yet been committed to battle . Time was at the essence and Masséna at once sent one of his " aides - de - camp " , Charles Oudinot , the son of Marshal Duke of Reggio , with orders to bring forward the Guard cavalry . The young Oudinot hastily set off and Masséna was impatiently checking his watch , counting every minute , pressed to commit this cavalry to what he saw as being a decisive action of the battle . Much to the general staff ' s stupefaction , Oudinot was soon seen returning without any cavalry following him . As soon as he saw him , Masséna furiously shouted from afar : " Where is the cavalry of the Guard ? " . The sweaty , dust - filled Oudinot needed a moment to catch his breath after his exhausting gallop but then explained that he was not able to fetch it . Oudinot had encountered the Guard cavalry deputy commander , General Louis Lepic , who sharply refused to commit his men , saying that he only recognised the Duke of Istria ( Bessières ) as commander and that without explicit orders from its commander , the Guard Horse Grenadiers and Dragoons would not draw their swords . In a staggering display of treachery , Bessières was absent from the field of battle , needlessly inspecting a series of ditches where the French army had passed a few days before . Unable to find the commander of the Guard in time , Masséna was forced to admit that the opportunity was lost . Two incidents spoiled this otherwise fine accomplishment for the British - Portuguese . One occurred when a British 14th Light Dragoon squadron pressed home a frontal attack on a French artillery battery and was mauled . In the second case , French cavalry caught some companies of the 3rd Foot Guards in skirmish order and inflicted 100 casualties . Masséna , however , was still aimed primarily at securing Fuentes de Oñoro . He sent forward massed columns of infantry from Ferey ' s division . The village , filled with low stone walls , provided excellent cover for the British line infantry and skirmishers , while the French were severely restricted in the little streets . At first , the French had some success , wiping out two companies of the 79th Highland Regiment and killing the regiment ' s commander , Lieut - Colonel Philips Cameron . But a counterattack chased Ferey ' s men out of the town . Drouet launched a second attack on the town . This time it was led by three battalions of converged grenadiers from IX Corps . With their old - fashioned bearskin hats , the grenadiers were mistaken for the Imperial Guard . Again , the British fell back . Drouet threw in about half of the battalions from both Conroux and Claparède ' s divisions , seizing almost the entire town . In response , Wellington counterattacked with units from the 1st and 3rd Divisions , plus the Portuguese 6th " Caçadores " . Led by the 88th " Connaught Rangers " Foot , this effort broke Drouet ' s attack and the tide began to turn . Low on ammunition , the French had to resort to the bayonet in a futile attempt to drive the British back . One party of 100 grenadiers was trapped in a tight spot and slaughtered to a man . Facing murderous volleys , the French halted and turned , being shot at as they withdrew , leaving their casualties behind . By sunset , French morale had plummeted and many companies were down to 40 % strength . The French artillery tried to bombard the new British line into submission , but they were outgunned by Wellington ' s cannon . Finally , with their artillery ammunition dangerously low , the French attacks came to an end . Wellington ' s men entrenched during the evening . After spending the next three days parading before the British position , Masséna gave up the attempt and retreated to Ciudad Rodrigo . He was furious because Bessières refused to fetch ammunition from the citadel . Consequences . Wellington had repelled the Army of Portugal , inflicting a great number of casualties , and was able to continue his blockade of Almeida . ( The numbers of losses vary according to different sources , from 2 , 200 to 3 , 500 French for the loss of 1 , 500 Allies , while another historian stated there were 2 , 800 French and 1 , 800 Allied losses . ) However , he acknowledged how dangerous the situation had been , saying later , " If Boney had been there , we should have been beat . " Indeed , Russian historian Oleg Sokolov noted that Wellington had committed a serious strategic error by following the French into northern Portugal , and that this decision could have had grievous consequences for the Anglo - Portuguese . Sokolov adds that , despite the various setbacks that he encountered before and during the battle , Masséna was still able to check Wellington ' s position at Fuentes de Onoro . Wellington himself did not mark the battle as a victory ; he also considered that he had unnecessarily extended his line , putting the 7th and Light Divisions in danger . Two nights after Masséna ' s withdrawal , Antoine Brenier ' s 1 , 400 - man French garrison of Almeida slipped through the British lines during the night . About 360 of the French were captured , but the rest got away when their British pursuers ran into a French ambush . This fiasco was blamed on Erskine and others . An infuriated Wellington wrote , " I have never been so much distressed by any military event as by the escape of even a man of them . " On reaching Ciudad Rodrigo , Masséna was recalled to Paris by a furious Napoleon to explain his actions ( although Napoleon had issued the order to return prior to the battle ) . He was replaced by Marshal Auguste Marmont . Masséna set off for France with a vast sum of gold , looted from Portugal and Spain . The defeated French marshal complained that Wellington " had not left him one black hair on his body — he had turned grey all over . " Interestingly , this battle also included a notable friendly fire incident . During the proceedings , a French infantry unit mistook their allies , the Hannovarian Legion , for an English battalion and opened fire on them . The unfortunate Hannoverians retreated hastily past the village , leaving over 100 dead . The reason is plain : the Hannovarian Legion wore red coats , and in the smoke and heat of battle the finer details of uniforms that might have distinguished them from British line infantry were easily overlooked .