 Following a fierce battle on two fronts , the British succeeded in routing the attacking French forces . A lack of support from the larger Spanish contingent prevented an absolute victory , and the French were able to regroup and reoccupy their siege lines . Graham 's tactical victory proved to have little strategic effect on the continuing war , to the extent that Victor was able to claim the battle as a French victory since the siege remained in force until finally being lifted on 24 August 1812 . 
