After the Battle of Roliça, General Sir Arthur Wellesley established a position near Vimeiro to cover a beachhead at Maceira Bay. Most of ,his reinforcements had arrived by 20 August and Wellesley planned to advance to Lisbon. His force consisted of eight independent infantry brigades, 17 cannons, 240 light cavalry and about 2,000 Portuguese troops him giving a total of 20,000 men. This was the first action of the Peninsular war when both the 29th Foot, in the 3rd Brigade under Major General Nightingall, and the 36th Foot, in the 2nd Brigade under Major General Ferguson fought on the same field.
Opposing him was General Junot’s 14,000-man army was organised into two infantry divisions and a cavalry division under Pierre Margaron. Henri François Delaborde’s infantry division contained two brigades under Antoine François Brenier and Jean Guillaume Barthélemy Thomières, while Louis Henri Loison’s division included two brigades commanded by Jean-Baptiste Solignac and Hugues Charlot. In addition, François Étienne de Kellermann commanded a 2,100-man reserve made up of four combined grenadier battalions made up of the grenadier company from each of Junot’s infantry battalions. The French were supported by 23 cannons.
The battle started with an attempt at an outflanking manoeuvre by the French but Wellesley was able to redeploy his army in time to meet this threat. Wellesley placed Anstruther’s and Fane’s brigades in front of Vimeiro, with Acland’s men in support. At first, his five remaining brigades held only the western ridge. Junot planned to send Thomières, Solignac and Charlot’s infantry brigades to capture Vimeiro, while Brenier’s 4,300-man brigade and some dragoons swung in a wide flanking manoeuvre to seize an empty ridge to the northeast of the village. Wellesley detected Brenier’s move and switched Nightingall (including the 29th Regiment), Ferguson (incuding the 36th Foot) and Bowes Brigades to the northeastern ridge. Once Junot realised that British troops occupied the ridge, he sent Solignac’s brigade to the right to assist Brenier’s attack. The French commander decided to launch his attack on the town immediately, instead of waiting for his flanking move to develop.
All the preliminary moves and countermoves caused a series of uncoordinated French attacks. First, Thomières’ 2,100-man brigade approached the British position. Supported by three cannons and screened by skirmishers, the brigade was formed into a column.
To counter the French skirmishers, Fane detached four companies of the 60th Regiment of Foot and the 95th Rifles. These outnumbered and outfought the French skirmishers, who fell back to the sides of the brigade column. Without their skirmishers in front of them, the French column blundered into the 945 men of the 50th Regiment. At 100 yards the British, formed into a two-deep line, opened fire. Several companies of the 50th began wheeling inward toward both flanks of the French column. Unable to properly deploy into firing line and unwilling to face the deadly enfilade fire, the French infantry fled to the rear, leaving their three cannons to be captured.
Soon after, a similar fate overtook Charlot’s brigade. In a very narrow column, it struck one battalion of Anstruther’s brigade, which had been hidden behind a crest. Before they could deploy, the French were taken in flank by a second battalion. Unable to effectively reply to the devastating British volley fire, Charlot’s men fled. Seeing the battle going against him, Junot committed his grenadier reserve to the attack. The first two battalions attacked the same area as the previous units and were thrown back. Kellermann swung the final two grenadier battalions wide to the right and succeeded in breaking into Vimeiro. But, counterattacked by units from Anstruther’s and Acland’s, these Frenchmen also fell back. The 20th Light Dragoons pounced on Kellermann’s retreating grenadiers and routed them. Excited by their easy success, the British horsemen charged out of control. They were met by Margaron’s French cavalry division and were routed in their turn.
As Brenier’s men had become lost in the hills, Solignac attacked the northeast ridge. This brigade changed tactics deploying in an attack formation with three battalions abreast. Even so, each battalion formed a column one company wide and eight companies deep. If the French intended to form into line once the enemy position was detected, they waited too long. They marched into the kill zone of Nightingall and Ferguson’s brigades before they could deploy. Smashed by British volleys, Solignac’s men fled.
Brenier’s brigade, marching to the sound of battle, came on four battalions abreast. At first they enjoyed success when they surprised and defeated two British battalions. Victorious, the French column pressed, but soon ran into the 29th Regiment in line and were stopped. The 29th was joined by the other two units, who had quickly rallied. Together, the volley fire of the three British battalions soon routed Brenier’s men.
At the Battle of Vimiero the 29th Regiment suffered the following casualties: Killed: 2 Rank and File. Wounded Brigadier-Major Andrew Creagh , 1 Serjeant, 10 Rank and File.
After the comprehensive French defeat, Junot offered complete capitulation. Nevertheless, Dalrymple gave the French far more generous terms than they could have hoped for. Under the terms of the Convention of Sintra, the defeated army was transported back to France by the British navy, complete with its guns and equipment and the loot it had taken from Portugal. The Convention of Sintra caused a massive outcry in Britain and, following an official enquiry, both Dalrymple and Burrard were blamed. Wellesley, who had opposed the agreement, was exonerated.