The People of Gibraltar
1462 - Gibraltar - The Spanish Fortress - Part 11
The Line Wall

It was the opinion of Cristóbal Rojas that prevailed at the end of the century. The old Marinid walls were occasionally renovated until they were completely remodelled in 1627. As Bravo da Acuña had proposed, the watch and flanking towers were dismantled and replaced with parapets for the artillery.

El Frattino began the construction of el Baluarte or la Plataforma de Santiago along the line of defences between Santa Cruz and la Puerta Nueva. Given the high location of Santa Cruz he considered it pertinent to have two forward defensive elements that might interact with each other with cross fires denying access to the Puerta de Carlos V (Southport Gate) and los Arenales Rojos (Red Sands) These would be Rosario and Santiago which would be able to control the defensive wall in which the Puerta de Carlos V had been constructed. 

Rosario (South Bastion) in the middle distance from Santiago (Flat Bastion)    (Pre1879 - From Captain Buckle’s Collection)

The construction of the first - Santiago - did not meet with Spannocchi’s approval as he found it ineffective despite the fact that its construction had finished by 1599. This dissatisfaction led to improvements being carried out during the first years of the 17th century.

Early 17th century - Cristóbal Rojas

The text translates as follows:
Top Text from left - “Reducto de Santa Cruz - This is the old wall of the town (Charles V) - Baluarte de Santiago, first platform, second, third, Casemates and platform of el Baluarte del Rosario.”
Second line of text - “Profile of the drop of the wall and the land from Santya Cruz to el Baluarte del Rosario.”
The two gates from left to right are labelled - “Puerta del Baluarte de Santiago” (Entrance to the Bastion) - “Puerta de la Ciudad”(Southport Gate)

By 1610 the Marquis of San Germán and Bautista Antonelli visited the fortification and became aware of the incorrect placing of the artillery platform brought about by the steepness of the ground on which it had been built. Their proposal stated that:
It is necessary to divide this Bastion (Santiago) into three parts so that each of them is level and the artillery can work properly.

Section of the bottom part of Charles V Wall showing the three levels of el Baluarte de Santiago as proposed by the Marquis of San Germán and Bautista Antonelli in 1610   (1627 - Luis Bravo de Acuña)

Numerous other platforms were built between the Old Mole and Europa Point. All of them were constructed with ample stages for artillery manoeuvrability, access stairs, and gunpowder bunkers. They were strategically placed along the Line Wall making flanking fire available across the intermediate walls. These platforms dominated all entry points along the littoral perimeter and any two could fire simultaneously against any of them.

 From north to south these were las Plataformas of San Andrés, Santa Ana, San Lorenzo, San Diego, San Francisco, and The Baluarte del Rosario.

Proposals for the improvement of the Fortifications of Gibraltar     (1778 - William Green)

My copy of Green's plan is not good enough to appreciate the finer details of Gibraltar’s Chief Engineers plans. However the scheme covers more or less a similar plan by Bravo de Acuña as well the one of the town which I have annotated above.
“A” refers to  the Prince of Orange demi-Bastion which replaced la Plataforma de Santa Ana.

Prince of Orange demi-Bastion    (1773 - William Green)

“B” is King’s Bastion which was built over la plataforma de San Lorenzo. “C” and “D” were San Diego and San Francisco which were converted into demi-bastions which formed part of a long stretch of curtain wall with the overall name of the Wellington Front. It was the last in Gibraltar to have been built by convict labour.

The Wellington Front     (1866)

As regards “E” and “F” as far as I know nothing remotely like the proposal was ever carried out either at Southport or along Charles V Wall.

Returning to the Spanish era . . . further south along the Arenales Colorados the defences were not as good as it was thought that the protection offered by the artillery of Rosario and of the Torre del Tuerto were sufficient.

Between these two the medieval wall and its flanking towers were useless other than to house a few fusiliers. The continual repairs made to these defences led to the construction of exterior counter-forts which were missing certain angles of fire and left some areas dangerously unguarded. By the start of the 17th century two covered structures were built - La Fuente del Chorruelo and the Medialuna de los Tres Reyes. The New Mole was protected by la Torre del Tuerto.

Southern Defences

In this area some of the more well-known and repeated events of the 1704 Anglo-Dutch assault took place. Once terrestrial communication had been cut when Prince Hesse and his 2 500 soldiers had disembarked in the isthmus, the Governor Salinas was asked to surrender. 

As the city decided to remain loyal to Phillip V it received an intense bombardment on the morning of the 3rd of August. As the guns that defended the New Mole were not properly mounted, English soldiers and marines disembarked and attacked the Torre del Tuerto which blew up under their feet. They nevertheless were able to advance against the southern defences and - as noted previously - were able to take hostages.

On their way towards the city they occupied a small coastal battery which has been repeatedly mistaken by different authors. This might possibly have been the Medialuna de los Reyes or perhaps a small battery which was hardly relevant to the Spanish defensive system and which would later be named Eight Gun battery.