Cadiz had been captured more than once in earlier wars, but always by an enemy who could attack from the sea. Neither the Isla de Leon nor the San Fernando line could be held against an attack supported by a fleet which came close in shore, and battered the works from flank and rear, or landed troops behind them. The sea, it may be remarked, is four fathoms deep to within a short distance (about 300 yards) of the shore, all along the south front of the Isla and the Isthmus, so that there was nothing to prevent a fleet coming close to the works. But against any naval attack Cadiz was, in 1810, absolutely secured by the predominance of the English fleet. There was no armed French vessel nearer than Bayonne or Barcelona, nor any possibility of bringing one round. All that was done by the besiegers in a three years’ leaguer was to build some gunboats in the northern inlets of the bay, and these they never dared to bring out into the open water. The real danger to Cadiz lay not from the sea side, nor on the Isla front, but from the inner side of the harbour and the east. Here a long spit of land runs out from beside the town of Puerto Real in the direction of Cadiz. It is called the Trocadero, from a village situated on its south-eastern side. At its extreme point is a fort named San José, while another fort, named San Luis, lies alongside of the other on a low mud-island. In advance of both, built right in the marsh, and surrounded by water at high-tide, was a third called Matagorda. These three forts were the outer defences of the harbour against a naval attack, and could cross fires with the town batteries and a castle called Puntales, which lies on the easternmost point of the isthmus, a mile from the battery of San Fernando. Matagorda is only 1,200 yards from Puntales, and 3,000 yards from the eastern point of the city of Cadiz. If the French took possession of it, and of the neighbouring San José and San Luis, they could bombard the Puntales castle and all the neighbouring section of the Isthmus, to the grave danger and discomfort of all who had to pass between the city and the Isla de Leon. They would also be able to annoy ships lying in all the eastern reaches of the great harbour. But before Victor arrived in front of Cadiz, San José, San Luis, and Matagorda were blown up, with the leave of the governor Venegas, by a detachment of seamen from the British fleet. There could, therefore, be no trouble from this direction, unless the enemy succeeded in restoring and rearming the three forts,--no easy task under the fire of the Puntales castle and the fleet. It was not till some months had passed that the struggle began for these ruined works, the only points from which the defence could be seriously incommoded.