Initial bombardment On 17 June, Wellington's army enveloped Salamanca, with the left wing going north of the city and the center and right wing circling to the south. The three columns joined on the north side of Salamanca and then advanced to the San Christobal heights. Wellington hoped that besieging the Salamanca forts would goad Marmont into attacking him on the heights. Only the
14th Light Dragoons and the British 6th Division entered the city to lay siege to the forts. The Spanish citizens were delighted that the French were gone and gave the Allies a joyous welcome in the
Plaza Mayor. Wellington set up his headquarters in the city while Major General
Henry Clinton's 6th Division invested the forts. In order to prepare the forts for defense, Marmont's sappers had demolished a large part of the old University quarter in the southwest part of the city. Wellington had been led to believe that the forts were hastily prepared medieval convents and that their reduction would be relatively easy. Because of this belief, the Allied army brought only four
18-pounder long guns, each with only 100 shot. In fact, the three convents were massively reinforced using masonry from the dismantled University buildings, oak beams, and earth. The convents had their walls doubled in thickness, their windows blocked up, their surroundings guarded by scarps, counter-scarps, and palisades. Mounting 30 cannons, the largest fort, San Vincente was located at the southwest angle of the old city wall. San Cayetano with four cannons was southeast of San Vincente. South of San Cayetano was La Merced with two guns that prevented the Allies using the Roman bridge over the Rio
Tormes. San Vincente and La Merced overlooked the Tormes and were virtually impregnable against an attack from the south and west. Only the north sides of San Vincente and San Cayetano appeared promising to attack. San Vincente was separated from San Cayetano and La Merced by a ravine that ran southwest into the Tormes. The three forts were designed to be mutually supporting; any column attacking one fort could expect to come under a crossfire from the other forts. The French garrison consisted of six flank companies from the 17th Light, and the 15th, 65th, 82nd, and 86th Line Infantry Regiments plus an artillery company. Duchemin of the 65th Line commanded 800 soldiers and 36 mostly light guns. The British 6th Division included the 1st Brigade under Major General
Richard Hulse, the 2nd Brigade led by Major General
Barnard Foord Bowes, and the Portuguese brigade under Brigadier General Conde de Rezende. The 1st Brigade was made up of the 1/
11th Foot, 2/
53rd Foot, 1/
61st Foot battalions, and one company of the 5/
60th Foot. The 2nd Brigade comprised the
2nd Foot, 1/
32nd Foot, 1/
36th Foot battalions. The Portuguese brigade included the 9th
Caçadores Battalion, and two battalions each of the 8th and 12th Line Regiments. Lieutenant Colonel
John Fox Burgoyne was the ranking engineer officer and Lieutenant Colonel May of the
Royal Artillery commanded the 18-pounders. Burgoyne chose a position for the 18-pounders north of San Vincente. On the night of 17 June, 400 soldiers from the 6th Division began to dig the battery position. The working parties had no experience in siege work and the French had the area under cannon fire and musketry all night. In the morning the trench was only knee-deep and the workers had to be pulled back under cover. That night an exploring party was discovered and several men wounded by the defenders. The besiegers added 300 sharpshooters from the King's German Legion to their force in order to suppress the fire of the defenders. May borrowed three
howitzers and two 6-pound cannons from the field artillery and put both cannons in the San Bernardo convent. These guns were too small to smash the walls, but their fire would annoy the defenders. By the morning of 19 June, the first battery was completed and the four 18-pounders and three howitzers opened fire, causing some damage to San Vincente. Meanwhile, two more battery locations were started, one to the west near San Bernardo and one to the east near the College of Cuenca. Two of the howitzers were moved into the Cuenca battery, but they came under such deadly fire that 20 gunners became casualties that day. On 20 June,
Colonel Alexander Dickson arrived with a train of six 24-pound howitzers from the Portuguese fortress of
Elvas. The three borrowed howitzers were sent back to the field artillery. Two of the 18-pounders were moved to the Cuenca battery and their fire brought down part of San Vincente's roof, killing some of its defenders. Seeing that his artillery was running low on ammunition, Wellington sent a request to
Almeida for an ammunition resupply convoy. The bombardment was suspended.
Relief attempt Having assembled his army, Marmont advanced toward Salamanca on 20 June, pushing back the Allies' cavalry patrols. Wellington posted his army with his right flank at
Cabrerizos on the Tormes and his left flank at
San Cristóbal de la Cuesta. From right to left, were the 1st, 7th, 4th, Light, and 3rd Divisions and then Pack's and Bradford's brigades. The 5th Division, Hulse's brigade of the 6th Division, and España's division were held in reserve. Major General Victor Alten's light cavalry brigade guarded the right flank while Colonel
William Ponsonby's light cavalry brigade covered the left. The heavy cavalry brigades of Major Generals
John Le Marchant and
Eberhardt Otto George von Bock were in reserve. The two remaining brigades of the 6th Division maintained the investment of the three forts. Marmont's troops occupied
Castellanos de Moriscos and then attacked
Moriscos. The
68th Foot repulsed three attacks but Wellington pulled the unit back into his main defense line that night. Wellington expected to be attacked on the morning of 21 June, but Marmont initiated no action because the divisions of Foy and Thomières and one dragoon brigade did not arrive until the afternoon. That morning, Wellington might have crushed his outnumbered adversary and his staff wondered why their chief did not attack. According to a letter he sent to
Prime Minister Robert Jenkinson, 2nd Earl of Liverpool, Wellington hoped to stage another defensive victory like the
Battle of Bussaco. That evening Marmont held a
Council of war in which Maucune and Ferey advised him to attack but Clausel and Foy persuaded him not to. On 22 June, British commander realized Marmont was not going to attack. Still hoping to provoke an attack, Wellington had the
51st Foot and the 68th Foot from the British 7th Division drive the French from a knoll near Moriscos. This was accomplished with a British loss of seven killed and 26 wounded. That night, Marmont's army withdrew to a position near
Aldearrubia with its left flank at
Huerta near the Tormes. On 23 June, Wellington sent Hulse's brigade back to Salamanca and ordered Clinton to renew the siege of the forts. He also sent Bock's cavalry to patrol the west bank of the Tormes opposite Huerta.
Assault On 23 June, Clinton renewed the siege of the three forts despite the handicap of having very little ammunition. The four 18-pounders only had 60 rounds altogether and the six howitzers had only 160 shells between them. The engineers and gunners decided to ignore San Vincente because it was too strong. Instead, they focused on reducing San Cayetano. With this in mind, one of the 18-pounders was moved to the San Bernardo battery in order to get an enfilade on a vulnerable point in San Cayetano. After firing all morning, the 18-pounders ran out of ammunition in the afternoon. San Cayetano was considerably damaged, but there was no breach in its walls. Despite this, Wellington ordered an assault to be carried out at 10 pm that night. The attacking force was made up of the six light companies from the brigades of Hulse and Bowes, approximately 300–400 men. Since there was no breach, the men carried 20 ladders in order to reach the parapet. The officers observed that, "the undertaking was difficult, and the men seemed to feel it". The assault was launched from some ruins near the Cuenca battery. As soon as the storming column burst from cover it came under deadly cannon and musket fire not only from San Cayetano, but from San Vincente as well. There were casualties from the first moment. Only two ladders were put up but no one dared to climb them, since by then it was clear that the attack was hopeless. The other ladders were poorly made and some fell apart as they were being carried. Bowes was slightly wounded at once while leading the assault. He dressed his wound and rushed back into the battle only to be killed at the foot of the ladders. The assault failed with a loss of six officers and 120 men killed or wounded. The British requested a truce to gather their dead and wounded, but the French refused and Bowes' corpse was not recovered until later.
Final bombardment The early morning of 24 June saw a heavy fog, accompanied by the muted sounds of musketry and by the occasional thud of a cannon firing. When the fog dissipated at 7 am, Wellington and his staff could see Bock's cavalry retreating before two French infantry divisions and a light cavalry brigade that had crossed the Tormes. The British army commander ordered
Lieutenant General Thomas Graham to take the 1st and 7th Divisions and Le Marchant's cavalry across the river at
Santa Marta de Tormes and block the French thrust. The French pressed ahead to the village of
Calvarrasa de Abajo beyond which they found Graham's divisions deployed in a strong position. Suddenly, the French turned around and fell back across the Huerta fords. The Allies did not pursue. Graham's troops soon returned to their previous positions on the east bank. Neither army budged on 25 June. On this day, soldiers of the 6th Division completed a trench along the bottom of the ravine, cutting off San Vincente from the other two forts. On the morning of 26 June, the ammunition convoy finally arrived. The artillerists moved all four 18-pounders into the San Bernardo battery and directed their fire at San Cayetano. Four howitzers were placed in the Cuenca battery and ordered to fire red hot shot into the roof of San Vincente. The bombardment began at 3 pm and continued all night long. Altogether, 18 separate fires started in the roof and tower of San Vincente and were put out by the garrison. A large amount of wood had been used by the French in order to strengthen the fort, and this provided the fuel. After four more hours of pounding on the morning of 27 June, the 18-pounders smashed a breach in the walls of San Cayetano. A new fire broke out in San Vincente; it ignited the main store of planks and threatened to explode the gunpowder magazine. Up until this time, the French return fire was intense, but the exhausted garrison's fire began to taper off. Wellington ordered San Cayetano to be stormed. The storming column formed in the ravine below San Cayetano. Just as the men were about to charge, a white flag appeared at the breach. The French commander asked for a truce, requesting a chance to communicate with Duchemin, and promising to surrender in two hours. Wellington demanded a surrender in five minutes, but the French officer continued to bargain. Despite this, the storming column came out of the ravine and rushed the fort. A few scattered shots wounded six attackers, then San Cayetano's garrison threw down their weapons. By this time, the fire in San Vincente was raging and a white flag waved there also. Duchemin asked for a three-hour truce, but Wellington repeated his earlier promise to storm the place in five minutes if no surrender was forthcoming. Duchemin tried to stall, but the 9th Caçadores emerged from the ravine and entered the fort. There was no resistance and the French flag was quickly hauled down. The source did not mention how or when La Merced surrendered. ==Result==