The combat of Arzobispo of 8 August 1809 was a minor French victory late in the Talavera campaign, which saw them force their way across the River Tagus. After their success at Talavera, the British and Spanish had been forced to retreat by the unexpected arrival of three French corps from the north west of Spain under Marshal Soult. The British slipped across the Tagus at Arzobispo on 4 August, and despite some delays the Spanish followed on the night of 5-6 August.
The Allied armies then moved west along the south bank of the Tagus, heading for the main road into Estremadura, leaving a strong rearguard to protect the river crossing. In total the Spanish left 8,000 men to guard the bridge (5,000 infantry and 3,000 cavalry), under the overall command of the Duke of Albuquerque. They had two crossing to protect – the bridge at Arzobispo and a nearby ford at Azutan. The bridge itself was strongly held, with a detachment of infantry defending the medieval towers in the middle of the bridge and gun emplacements covering the approaches to the bridge, but the Spanish somewhat overestimated the difficult of the ford.
After spending 7 August investing the river, Soult’s men discovered that the deep channel in the river was close to the north bank, and after that the river was only two or three feet deep. Once the French cavalry was past this deep channel, it could fan out to attack any part of the opposite bank. Their chance of success was greatly increased by Albuquerque’s deployment – most of his men were held back from the river, with only one cavalry regiment watching the ford, and two infantry battalions at the bridge.
Soult launched his attack at 1.30pm, during the siesta. He sent his entire force of 4,000 cavalry to attack across the ford, supported by one brigade of infantry. A second infantry brigade was to watch the bridge, but was only to attack once the French had crossed the ford. Caulaincourt’s brigade of dragoons, 600 strong, led the attack, and quickly swept away the Spanish cavalry. The Spanish responded by sending one battalion of infantry from the bridge, but it failed to form square in time and was cut up by the French cavalry. Over the next half hour the French were able to pass the rest of their cavalry across the ford.
This was the signal for the start of the attack on the bridge. Despite their strong position, the Spanish defenders of the bridge could see that their line of retreat was about to be blocked, and so after firing a couple of volleys fled east, away from the rest of Albuquerque’s force. Only now did the rest of the Spanish force come into action. While the remaining infantry formed up on a hill above the bridge, Albuquerque led his 2,500 cavalry in a desperate charge against the leading French cavalry. Having wasted a crucial half an hour while the French were crossing the ford, the Spanish attack was carried out before the cavalry had a chance to form up properly, and was quickly repulsed by the more organised French. Seeing the cavalry defeated, the infantry abandoned their position, and retreated across the hills to safety.
The Spanish cavalry suffered heavily in the battle at the ford, losing 800 killed and wounded and 600 prisoners, leaving only 1,100 of the original 2,500 men still with the colours. The French captured 16 Spanish guns at the bridge, and fourteen of the guns they had lost at Talavera. Despite their success, the French crossed the Tagus too late to have any chance of catching the main Allied army. An attempt to cross the river further west, at Almaraz, failed after Ney’s men could not find the fords they had been sent to cross. The British and Spanish took up a strong defensive position around Almaraz. Even Soult realised that this position was too strong to be assaulted, and proposed invading Portugal from Ciudad Rodrigo, but King Joseph opposed this plan. Instead the armies that had threatened Wellington were dispersed to deal with other threats.