Battle of the Pyrenees The Battle of the Pyrenees was a large - scale offensive launched on 25 July 1813 by Marshal Nicolas Jean de Dieu Soult from the Pyrénées region on Emperor Napoleon ’ s order , in the hope of relieving French garrisons under siege at Pamplona and San Sebastián . After initial success the offensive ground to a halt in face of increased allied resistance under the command of Arthur Wellesley , Marquess of Wellington . Soult abandoned the offensive on 30 July and headed toward France , having failed to relieve either garrison . The Battle of the Pyrenees involved several distinct actions . On 25 July , Soult and two French corps fought the reinforced British 4th Division and a Spanish division at the Battle of Roncesvalles . The Allied force successfully held off all attacks during the day , but retreated from the Roncesvalles Pass that night in the face of overwhelming French numerical superiority . Also on the 25th , a third French corps severely tried the British 2nd Division at the Battle of Maya . The British withdrew from the Maya Pass that evening . Wellington rallied his troops a short distance north of Pamplona and repelled the attacks of Soult ' s two corps at the Battle of Sorauren on 28 July . Instead of falling back to the northeast toward Roncesvalles Pass , Soult made contact with his third corps on 29 July and began to move north . On 30 July , Wellington attacked Soult ' s rearguards at Sourauren , driving some French troops to the northeast , while most continued to the north . Rather than use the Maya Pass , Soult elected to head north up the Bidassoa River valley . He managed to evade Allied attempts to surround his troops at Yanci on 1 August and escaped across a nearby pass after a final rearguard action at Etxalar on 2 August . The French suffered nearly twice as many casualties as the Allied army . Background . After the decisive French defeat at the Battle of Vitoria , Marshal Soult consolidated the remnants of four armies into a single force of 80 , 000 troops . Soult ordered General of Division Jean - Baptiste Drouet , Comte d ' Erlon commanding one corps ( 21 , 000 men ) to attack and secure the Maya Pass . General of Division Honoré Reille was ordered by Soult to attack and seize the Roncesvalles Pass with his corps and the corps of General of Division Bertrand Clausel ( 40 , 000 men ) . Marshal Soult ’ s plan was to relieve the siege at Pamplona first , then swing the army westward to relieve the siege at San Sebastián . Forces . Clausel ' s Lieutenancy ( army corps ) of the Left consisted of the infantry divisions of Generals of Division Nicolas François Conroux , Edmé - Martin Vandermaesen , and Eloi Charlemagne Taupin . Conroux ' s 4th Division had 7 , 056 men in nine battalions ; Vandermaesen ' s 5th Division counted 4 , 181 troops in seven battalions ; Taupin ' s 8th Division numbered 5 , 981 infantry in nine battalions . D ' Erlon ' s Lieutenancy of the Center included the infantry divisions of Generals of Division Jean Barthélemy Darmagnac , Louis Jean Nicolas Abbé , and Jean - Pierre Maransin . Darmagnac ' s 2nd Division counted 6 , 961 troops in eight battalions ; Abbé ' s 3rd Division was made up of 8 , 030 soldiers in nine battalions ; Maransin ' s 6th Division had 5 , 966 men in seven battalions . Reille ' s Lieutenancy of the Right had the divisions of Generals of Division Maximilien Sebastien Foy , Antoine Louis Popon de Maucune , and Thomas Mignot de Lamartinière . Foy ' s 1st Division numbered 5 , 922 soldiers in nine battalions ; Maucune ' s 7th Division had 4 , 186 infantry in seven battalions ; Lamartinière ' s 9th Division comprised 7 , 127 troops in 10 battalions . Each Corps had a single cavalry regiment attached for scouting purposes , for a total of 808 horsemen . The French Reserve under General of Division Eugene - Casimir Villatte held the defences on the lower Bidassoa River near the Bay of Biscay . The reserves numbered 9 , 102 French troops in 14 battalions , 2 , 066 Germans in four battalions , 1 , 349 Italians in three battalions , 1 , 168 Spanish in three battalions , 1 , 550 French National Guards , and 2 , 019 King ' s Guards in three battalions , the last being the remnant of Joseph Bonaparte ' s bodyguard . In addition , General of Division Pierre Benoît Soult commanded 3 , 981 light cavalrymen in 10 regiments and General of Division Anne - François - Charles Trelliard led 2 , 358 dragoons in six regiments . The two cavalry divisions remained in the rear . There were about 7 , 900 gunners , sappers , wagon drivers , and other troops . General of Brigade Louis Emmanuel Rey and 3 , 000 troops garrisoned San Sebastián while General of Brigade Louis Pierre Cassan held Pamplona with a 3 , 500 - man garrison . At Bayonne were 5 , 595 French conscripts . Altogether , Soult had 99 , 906 troops under his orders . Of this total he used 63 , 572 men in his offensive . Wellington defended the line of the western Pyrenees with a covering force of 62 , 000 men . These faced to the northeast , with the left anchored on the Bay of Biscay at the mouth of the Bidassoa River . From left to right , he deployed the following infantry divisions : Major General Kenneth Howard ' s 1st on the coast , Major General Charles Alten ' s Light at Lesaka , Lieutenant General George Ramsay , 9th Earl of Dalhousie ' s 7th at Etxalar , Lieutenant General William Stewart ' s 2nd at the Maya Pass and Elizondo , Major General Francisco Silveira , Count of Amarante ' s Portuguese near Izpegi Pass , Lieutenant General Lowry Cole ' s 4th at Roncevaux Pass and Major General Pablo Morillo ' s Spanish also at Roncevaux . In reserve were Major General Denis Pack ' s 6th Division at Doneztebe , and Lieutenant General Thomas Picton ' s 3rd Division at Olague , plus other Portuguese and Spanish units . Cavalry being of little value in the mountains , Wellington stationed most of his far to the rear , except for two light dragoon brigades . The Siege of San Sebastián was conducted by Major General James Leith ' s 5th Division and other units under the direction of Lieutenant General Thomas Graham . Pamplona was besieged by General Henry O ' Donnell , 1st Count of la Bisbal ' s Spanish division and other units . Battle . Maya and Roncesvalles . The surprise offensive opened on 25 July 1813 . The passes of Maya ( north of Pamplona ) and Roncesvaux ( northeast of Pamplona ) were both weakly held by the allies spread over a 50 - mile front from Pamplona to the sea . After breaking through the Maya Pass , d ' Erlon was to move southwest through the Baztan valley to seize the Pass of Velate at , north of Pamplona . After storming Roncesvaux Pass , Clausel and Reille were instructed to march southwest toward Pamplona . Soult had trouble securing rations for his soldiers , so he launched his offensive with only four days ' rations . The responsibility for Maya Pass lay with Stewart ' s 2nd Division . That morning , Stewart decided that the French would not attack , left the brigades of Major General William Pringle and Lieutenant Colonel John Cameron in the valley and rode to Elizondo , ten miles to the south . Some French soldiers were seen and light companies were sent up in support of the picket . When the French attacked in force , the British forces in the valley had to climb to the pass in full kit . By the time they got up , the picket force was wiped out and 10 , 000 of d ' Erlon ' s men occupied the pass . In the Battle of Maya , Pringle opposed Darmagnac ' s division , while Cameron faced the rest of the French corps . The 4 , 000 British tried manfully to retake the pass , but they were unable to do so . On the other hand , the narrowness of the defile helped the British to hold off d ' Erlon ' s immensely superior force . When Stewart returned at 2 : 00 pm , he pulled the redcoats back to a second position . By 3 : 00 pm , the British were on the verge of disaster . At this point , Major General Edward Barnes ' s brigade of Dalhousie ' s 7th Division arrived from the west to strike d ' Erlon in the flank and the battle died down . The British lost 1 , 610 men and four cannons out of 6 , 000 , while French losses numbered 2 , 100 out of 20 , 900 . That evening , Lieutenant General Rowland Hill authorized a retreat to Elizondo . D ' Erlon worried about Barnes ' s incursion and pursued very cautiously the next day . He only advanced six miles on the 26th . Cole held Roncesvalles Pass with his 4th Division , Morillo ' s Spanish Division and Major General John Byng ' s brigade of the 2nd Division , a total of 11 , 000 men . From 6 : 00 to 9 : 00 am , Byng ' s brigade took the brunt of Clausel ' s assault in the Battle of Roncesvalles , while Cole rushed up reinforcements . Cole fended off the French until 5 : 00 pm when thick fog rolled in . The Allies lost 350 men while French casualties were about 530 . Troubled by a small French probe of his right flank and fearful that 36 , 000 Frenchmen would swamp him out of the mist , Cole quit the area and retreated toward Pamplona , though he had been ordered to hold the pass " to the utmost " . A worse mistake in Wellington ' s eyes was Cole ' s failure to report his actions in a timely manner . When Picton appeared with his 6 , 000 - man 3rd Division , Cole convinced him to retreat also . Because of the fog , the French did not realise that the British had decamped until the next morning . Clausel pursued , but did not come into contact with Cole ' s rear guard until late in the afternoon . Meanwhile , Reille ' s corps attempted to use an alternate path across the mountains and wound up marching in a circle . A push on 27 July from Roncesvalles Pass by troops personally commanded by Marshal Soult , got within 10 miles of Pamplona . However , Picton ' s British and Portuguese forces made a stand on an excellent defensive position near the village of Sorauren , just north of Pamplona . Believing d ' Erlon ' s corps to be the main French attack and receiving no information from Cole , Wellington spent 26 July setting up his defences in the direction of Maya Pass . Leaving Hill in charge at Elizondo , he then rode toward Pamplona on 27 July to find out what was happening . He ordered Pack ' s 6th Division to join Cole and Picton . Sorauren and Soult ' s retreat . On 27 July , Wellington joined the 17 , 000 British and Portuguese force at Sorauren . To Clausel ' s intense frustration , Soult decided to wait for Reille ' s tardy corps to arrive and even took a nap . The next day , the Battle of Sorauren was fought when Soult ' s 36 , 000 men tried unsuccessfully to defeat the 24 , 000 allied forces in front of Pamplona . The Allies lost 2 , 652 casualties while French losses were probably heavier . Hill ' s corps , blocking d ' Erlon , was pulled back by Wellington toward Sorauren . But d ' Erlon was never able to reach Sorauren to help Soult . Instead , when d ' Erlon ' s cavalry made contact with Soult on the morning of 29 July , the French Marshal decided to move to the north rather than retreat northeast toward Roncesvalles . As 30 July dawned , Soult ' s men could be seen retreating east to west across the British front . Now reinforced by his 7th Division , Wellington ordered an attack . The French clung to Sorauren village in a bitter fight before being driven away . The British reported 538 casualties while French losses were much heavier . Cut off by the sudden British offensive , Foy ' s division at the east end of the French line retreated by way of Roncesvalles Pass to the northeast . Foy was joined by elements of Reille ' s and Clausel ' s commands so that he took as many as 12 , 000 men with him . Meanwhile , d ' Erlon led the rest of the French army in a retreat to the north , pushing back Hill ' s forces back just enough to get through . On 30 July at Beunza , Abbé ' s division of d ' Erlon lost 750 casualties , while the Allies lost 1 , 056 , including 156 British and 900 Portuguese . Instead of retreating over Maya Pass as Wellington expected , Soult marched north up the Bidassoa River valley . At Yanci , part of Major General Francisco de Longa ' s Spanish division blocked a key bridge . For two hours , without support from the rest of their division , a battalion of the 2nd " Asturias " Regiment held off d ' Erlon ' s entire corps . Finally , five French battalions stormed the bridge and Soult ' s defeated army crossed over it . Too late to block the retreat , Alten ' s Light Division arrived from Leitza and fired into the gorge from above , causing chaos in the French column . His starving army fast disintegrating into a mob , Soult swung northeast through Etxalar ( Echelar ) and reached the French frontier via the Col de Lizarrieta at on 2 August . On that day , elements of Conroux ' s and Lamartinière ' s divisions fought a rearguard action at Etxalar against Major General Robert Ross ' brigade of Cole ' s division , Barnes ' brigade , and the 95th Rifles . The French suffered about 300 casualties , while inflicting a loss of 368 killed , wounded , and missing on their pursuers . Meanwhile , over 1 , 000 French wounded were abandoned and captured by the Allies . Conclusion . Soult failed to relieve the sieges at San Sebastian and Pamplona , suffered about 13 , 000 casualties , and had to withdraw to French soil weakened and demoralised . Soult ' s army lost 1 , 313 killed , 8 , 582 wounded , and 2 , 702 captured . Out of 1 , 318 French officers , 423 became casualties . Wellington ' s total losses for the campaign were 7 , 000 . The next action was the Battle of San Marcial at the end of August .