Had the French been commanded by an enterprising general there is little doubt that they could have carried the town by assault, but Tesse, in his over caution, waited until success was a certainty.

The alarm in Barcelona was great, and the king sent messenger after messenger to Peterborough to urge him to come to his relief; but, daring as was the earl when he considered success to be possible, he would not venture his little force upon an enterprise which was, he felt, hopeless, and he knew that the only possible relief for the city was the arrival of the English fleet.
Early in March Admiral Sir John Leake and Baron Wassenaer had sailed from Lisbon with the combined fleet in accordance with Peterborough's orders; but the wind was contrary, and it was fully six weeks after starting that they reached the Straits, where they were joined by Captain Price with a small squadron, on board of which were two English regiments.

It was not until the 24th of April that they sailed from Gibraltar.
On reaching Altea they received news that another squadron had sailed from Lisbon to join them, and in spite of the warm remonstrances of General Stanhope, who commanded the troops on board, the Dutch and English admirals determined to await the arrival of the reinforcements before sailing to give battle to the fleet of the Count of Toulouse before Barcelona.
On the 3d of April Sir George Byng arrived at Altea with some ships from Ireland, and the next day Commodore Walker, with the squadron from Lisbon, also arrived; but the wind was now contrary, and although the fleet set sail, for three days they made no progress whatever, and each hour so wasted rendered the position of the besieged at Barcelona more and more desperate.

While lying at Altea General Stanhope had sent a message to Lord Peterborough telling him that he would use every means in his power to hasten Sir John Leake's movements, and that he would give him timely notice of the approach of the fleet.
He said that as it was of the utmost importance that the enemy should remain in ignorance of the approaching succors, his messenger should carry only a half sheet of blank paper, so that if he were taken by the enemy they would learn nothing from his dispatch.

When the fleet sailed he sent off a second messenger, who got safely to the earl, and delivered his blank dispatch.