Siege of Badajoz; 3/27th (Inniskillings) introduction to the Peninsular War.

The Second Siege of Badajoz during the Peninsular War marked the beginning of the Young Inniskillings' (3rd Battalion) war service.

The French had captured Badajoz from the Spanish during the First Siege of Badajoz in January 1811. Badajoz, some 6 kilometres from the Portuguese border, blocked the Anglo-Portuguese Army's advance into Spain and it was therefore essential that the allies capture the city. General Beresford's troops started operations against the French held fortress city in April 1811.

However, failure by the government in London to provide Wellington's army with the resources for a siege train and then Wellington's decision to undertake the siege, despite the lack of an adequate siege train, was an inauspicious start. Moreover, Wellington's direction to Beresford to take the surrounding forts of San Cristobal, Picurina and Pardeleras as preliminary operations meant that Beresford's forces and the already inadequate siege resources were split. Beresford's Chief Engineer was unable to begin the siege until May and this combination of errors meant that siege operations suffered from combined attacks and fire from the forts as well as from Badajoz.

On 10 May, the French made a sortie from Badajoz and caused havoc amid the troops preparing a gun battery position and its covering party. In this action, the 3rd Inniskillings acquitted themselves with distinction. Beresford, on hearing of the approach of a French army, raised the siege on 12 May and withdrew in good order by 15 May. There would be one more failed siege in June 1811, before, and at great cost to the allies, Wellington finally ejected the French from Badajoz in 1812.