Battle of Campo Maior

Battle context

At Campo Maior on 25 March 1811, an Anglo-Portuguese cavalry force under Long, acting as the advance-guard of Beresford's army, intercepted a French column under Latour-Maubourg escorting a convoy of siege artillery. The engagement produced an outcome that undermined what had been an initial Allied tactical success: a reckless pursuit by part of the Allied cavalry led to an erroneous report that those horsemen had been captured en masse. Beresford halted his forces on the strength of that false intelligence, allowing the French to disengage and retain their artillery train. The loss of the opportunity to seize the siege cannon was a tangible operational setback, as those guns remained available to French forces for subsequent operations in the Peninsular campaign. The episode also highlighted the risks of uncoordinated cavalry pursuit and the consequences of faulty battlefield reporting on command decisions.