The combat of Bilbao (10 April 1813) was an unsuccessful Spanish attempt to capture the city while it was weakly defended, but failed after one of the key forces failed to arrive in time to support the initial attack.
Bilbao was one of the main French bases in Biscay, but in early April it was unusually weakly defended. General Clausel, the French commander in the north of Spain, left the city on 30 March to move south to Vittoria to join up with Taupin’s and Foy’s divisions, newly arrived from the Army of Portugal. He planned to combine his own forces with the newly arrived troops to attack the Spanish leader Mina. At the same time General Palombini’s Italian Division had been send east to attack the Biscayan headquarters at Guernica. An attack on 2 April failed, but a second attack on 5 April ended in success. Palombini then attempted to trap the retreating Spanish further to the east, but failed. By 9 April he was at Bergara, on the main road to Bayonne, 30 miles to the east of Bilbao. Bilbao itself was defended by 2,000 men under General Rouget.
The Spanish were able to concentrate quite a large force against him. In the east the Biscayans and the troops of El Pastor (Gaspar de Jauregui) had been able to escape from Palombini’s pursuit after Guernica and were free to attack from the east. In the west Longa and Mendizabal had been attempted to prevent the French from taking the port of Castro-Urdiales, but when Clausel decided to temporarily lift that siege they were left free to attack Bilbao.
The Spanish plan was to attack on both sides of the Nervion River at the same time, forcing Rouget to split his forces. The attack in the east began on time, and Rouget’s troops were under very heavy pressure. However Mendizabal’s main force didn’t arrive in time to support this attack, and Rouget was just about able to hold on.
News of the attack quickly reached Palombini, who arrived at Bilbao after two forced marches. He arrived in time to save the city, and forced the Spanish to retreat. He then made another attempt to capture the Biscayan troops, who had once again retreated to Guernica, but once again they were able to escape with the help of the Royal Navy. Palombini managed to capture some of the Spanish baggage on 14 April, but then abandoned the pursuit and returned to Bilbao, where he prepared to resume the siege of Castro-Urdiales.