He could not spare men from his own scanty force to guard the roads between the city and the castle, but he had posted a number of the armed Spanish peasants who were in the pay of the army in a narrow gorge, where, with hardly any risk to themselves, they might easily have prevented the horsemen from passing.

The peasants, however, fired a hurried volley and then fled in all directions.
Lord Peterborough learned a lesson here which he never forgot, namely, that these Spanish irregulars, useful as they might be in harassing an enemy or pursuing a beaten foe, were utterly untrustworthy in any plan of combined action.

The succor, therefore, reached Montjuich in safety; two hundred of the men dismounted and entered the fort; the remainder, leading their horses, returned to Barcelona.
The Marquis de Risbourg had no sooner entered the fort and taken the command than he adopted a stratagem which nearly proved fatal to the English hopes of success.

He ordered his men to shout "Long live Charles the Third!" and threw open the gates of the fort as if to surrender.

The Prince of Hesse Darmstadt, who commanded at this point, was completely deceived, and he ordered Colonel Allen to advance with two hundred and fifty men, while he himself followed with a company in reserve, believing that the Spanish garrison had declared for King Charles.
The British advanced eagerly and in some disorder into the ditch, when a terrible fire of musketry was suddenly opened upon them from the front and flank.