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St. Jago's Bastion / Flat Bastion

Ref: HLFP3/200

Flat Bastion is a bastion that projects southward from the Charles V Wall built in the late 16th Century. A flat bastion is one built in the middle of a curtain, or enclosed court, when the court is too large to be defended by the bastions at its extremes.

At the time, no wall existed protecting the suburbs of the town from the South. Pedro Barrantes Maldonado writing on the pirate raid that sacked the town in 1540 noted that:

This suburb is only defended on one side and that is the side by the sea

Following the assault and looting of Gibraltar by the pirates under the command of Hayreddin Barbarossa, the Emperor Charles V promised to reinforce the defences of city. The first of these military experts was Benedetto de Ravenna, the first Italian to be given the title of Engineer of the Crown of Castile. He had previously visited other fortified towns along the coast of Andalusia, including the Rock in 1534. Essential repairs were immediately carried out under his advice, following consultation with the Mayor of Gibraltar, Don Álvaro de Bazán.

Baldassare Albianello of Padua arrived a year later and he too recommended that certain repairs be undertaken on the southern defences, with works being carried out by Luis del Toro. However, due to lack of funding work did not start until 1552 when the celebrated Milanese engineer, Juan Bautista Calvi was sent to the Rock. Calvi began work to build a wall from the sea to a casemate at the foot of the inaccessible cliff [Baluarte de Santa Cruz]. From the top of this cliff, he built a second wall, which ran from West to East until he reached the top of the Rock, at a point known as La Quebrada.1

A third wall ran along the cliff connecting to the base of the second wall.

Alonso Hernández del Portillo, writing in the early 17th Century, described the works as follows:2

 ‘He (Calvi) built a wall to protect the south side of the City (for as I have already mentioned it was not walled on the southern side) which stretched from east to west, from the sea to a casemate he built at the foot of an inaccessible cliff…..and this wall would command the sand banks close to the City, and from there the garrison would be able to threaten any enemies who tried to approach the first wall which protected the City itself and the gate known as ‘New’ so that the enemy would not be able to find protection from our men on the third wall above.’

This third wall mentioned by Portillo was to extend from the top of the inaccessible cliff to the base of the second or zigzag wall creating an enfilade, which in the words of Portillo would have inflicted serious losses to any enemy action attempting to storm the main city walls and the ‘New Gate’ [Puerta de África]. He also drew up plans for two defensive positions to the south of the town, where the South Bastion and Flat Bastion now stand, but due to ill health Calvi only designed the planned works but did not stay for its execution. It was probably another Italian, Amodeo Agostino, who initially constructed Calvi’s first wall but these works were cut short following his death in 1571.3

Sketch of Gibraltar by Anton van den Wyngarde, 1567.

Sketch of the South Front by Anton van den Wyngaerde, 1567.

Thus by 1567, only a long stretch of wall existed along the East to West axis with no protection to the main gatehouse except by an old mediaeval Moorish tower [La Torre de la Zebrera] on the sea wall and the semi-bastion or casemates of Santa Cruz along the inaccessible cliff. This is evidenced by the contemporary sketches of Anton van den Wyngaerde dated to this time.

Portillo states that although some engineers commissioned by Phillip to complete the works continued with Calvi’s fortification plans, others (probably El Fratino) decided against it and so his original plans were never put into effect.4

In 1575, another Italian engineer, Giovan Giacomo Paleari Fratino was commissioned by Phillip II to complete the fortifications in Gibraltar. El Fratino disapproved of Calvi’s recommendations and discarded the construction of the traverse along the cliff edge that was to join the first and second wall. Furthermore, El Fratino ordered that all work done on Calvi’s stepped or zigzag (en crémaillère) second wall was to be demolished. Work on the traverse ceased, but Philip II's chief engineer Tibúrcio Spannocchi refused to allow the demolition of the zigzag wall, and it was eventually finished in 1599. It is today the upper portion of Charles V Wall.

El Fratino meanwhile built his own wall running straight up from the precipice above the end of the lower wall, which was to be known as Phillip II wall, although it became mistakenly referred to as the Moorish Wall by the British.

He also began construction of a small bastion known as Baluarte de Nuestra Señora del Rosario (Bastion of Our Lady of the Rosary) on Calvi’s first wall so named after a hermitage of the same name, which stood nearby. This bastion was built on the site of the old Moorish gate known as the Gate of Algeciras. Along this wall, a second bastion was built in the shape of a flat bastion. Both bastions provided casemented gun positions that enfiladed the ditch across the Gate of Africa.

The construction of a flat bastion distending outwards from the main wall necessitated the extension of the height of the curtain by at least 10 feet along the entire length of the curtain. Another reason for the extra height required for the curtain was presumably to accommodate the third platform that now stood at least 600 feet above the second platform.  These works were probably the ones referred to by Bravo de Acuña in 1627. The extraordinary height of the curtain wall along the first and second platforms meant that no actual parapet and steps were built along this section of wall – the only section in the entire curtain – as the height made it virtually unclimbable. The original parapet masonry is still visible today all along the south facing part of the curtain wall.

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Continuation of the original parapet wall.

Construction of the Flat Bastion necessitated the elevation of the original height of the 1540 works along the lower sections of Charles V Wall.

Thomas James first suggested that the design of these works were carried out according to the instructions of the German military engineer Daniel Specklin, a claim supported by other historians since then and most recently in Hughes and Migos Strong as the Rock of Gibraltar.5

James offers no sources to back his claim and there is no evidence Specklin ever visited Spain, let alone Gibraltar, neither was he included in the list of engineers employed in Spain during the 16th Century.6 When construction of Charles V wall first began in 1540, Specklin would have been four years old and sixteen when Calvi presented his own designs.7 When Specklin’s book, Architectura von Vestungen, was published in 1589, both South Bastion and Flat Bastion had already been built. Specklin was in any case not inventing the wheel as far as new bastion fortifications were concerned, as the Italians had been the leading innovators of the new trace italienne style of fortification developed in Italy during the late 15th Century and early 16th Century, almost a century before Specklin was born. However, Specklin’s sketches includes a bastion and supporting flat bastion almost identical to the South Bastion and Flat Bastion in Gibraltar, and in his book’s introduction Specklin claimed that he designed the defences for Gibraltar – the only place referred by name in his book. As Gibraltar was already developing a reputation as an impregnable fortress, it would definitely have been in Specklin’s personal interest to claim responsibility for the construction of its defences to promote his book. Furthermore, it is clear that his entire fortress design collection, even those attributed to Gibraltar were actually generic designs and not place specific. As neither Calvi’s nor El Fratino’s designs for the South Front defences have survived, it is impossible to know if Specklin drew inspiration from the Italian engineers or indeed if Spanish engineers later adapted their fortifications to incorporate Specklin’s ideas into their own.

Sketch of an orillon and a flat bastion included in Daniel Specklin's Architectura von Vestungen (1589). This design is very similar to Gibraltar's South Front defences, including the upper zigzag wall.

Map and Fortifications of Gibraltar, 1597 (unknown).

The oldest map showing the South Front defences is dated to 1597, some eight years after Specklin’s published his ideas. Interestingly, the description of the South Bastion appears to show the words ‘sin acabar’ or not yet completed.

Works on the Flat Bastion had certainly not been completed in 1608 when Phillip II sent Captain Cristobal de Rojas to Gibraltar. Rojas had inspected the southern defences in 1598 and gave his recommendations but did not stay to supervise the works. He returned by Royal Order in 1609 to complete the fortifications in Gibraltar:8

Starting from the front towards our Lady of Europe, and continuing along the platform of Santiago (Flat Bastion) and the platform of El Rosario (South Bastion), tower of San Francisco (Wellington Front) and the rest of the old walls right up to the platform of El Cañuto (North Bastion)…’

Amongst his sketches, Rojas drew a cross section of the lower part of the wall that clearly shows the three-tiered platform of Santiago, including an access gate to the third (lower) tier of the platform. This gate stands above Prince Edward’s Gate next to the orillon.

 Cristobal Rojas plan of the South Front, 1608.

Cristobal Rojas cross section of the baluarte de Santiago, 1608.

Cristobal Rojas plan for the left flank of the South Front above the Charles V Wall and connecting to the lower section of the zigzag wall.

When in 1577, Bravo de Lagunas, Commander of Los Hornos, ordered a general muster of the militia in the city, he found 351 inhabitants with harquebus, 92 crossbowmen and 32 men with halberds, pikes, and spears, as well as 86 unarmed men. He also noted that there were 24 cavalry, although their horses grazed in meadows outside the city for six months of the year. Both the city and fortress lacked soldiers in charge of its defence. Spannocchi, reporting towards the end of the 16th Century noted that the city consisted of around a thousand families, equivalent to about five thousand inhabitants. Among them were eight hundred men of war.

When Bravo de Acuña arrived in Gibraltar in 1627, he was quite impressed with the works already carried out along the new South Front, recommending instead the completion of the old and new moles as well as repairs to the castle and construction of new barracks for 600 men.

Bravo drew detailed plans of Gibraltar’s defences including the retired batteries of the Flat Bastion. The eastern and southern walls of the bastion was defended by a wide ditch. A small door labelled Puerta del Soccorro (probably a sally port) was located along the top of the eastern wall and protected by the flanking fire of the semi-bastion of San Felipe (Lower Genoese Battery) and other walls on the cliffs above. Although the Flat Bastion consisted of three platforms, only the lower ones were used for firing guns and protect the Southport gate. The third platform, raised much higher than the other two was purely to fire upon the lower sections of the bastion itself should it be successfully assaulted and cover the entrance to the town located on the second level. No guns were ever placed here when the British captured the Rock either.

Bravo de Acuñ's plan of South Bastion and Charles V Wall, 1627.

After 1627, no further works of note were carried out on Gibraltar’s fortifications so that by 1704, parts of the old sea wall had collapsed allowing Captain Jumper and his marines to breach the sea wall and attack La Torre del Tuerto overlooking the new mole. The defences along the South front, including the Flat Bastion were never tested as the city surrendered soon after the landings.

For most of the first half of the 19th Century, British engineers directed most of their resources in reinforcing the North Front defences. In 1769, William test drew an elevation of the bastions and curtains which defended the South Front of the town. The plan shows that there were two eaves or sentry towers located at the west and east shoulders of the bastion. Test also noted that from the west shoulder of the Flat Bastion right up to the demi-bastion along the cliff edge there was no longer a ditch, covered way or glacis. The height of the wall was about 60 feet (18.288m) according to the plan with those of the Flat Bastion projecting outwards being slightly lower.

The first real description of the Flat Bastion is provided by Colonel James in 1771: 9

Near the centre of this curtain is constructed a large flat bastion, to augment the defence, and to cover the curtain from the high ground opposite to it. This work is raised on the declivity of the hill, which obliged Speckel the engineer to build traverses of masonry across this bastion, serving for flanks. The flank next the south bastion has an epaulement, and a retired flank with two embrasures, and three more on the face. The communication to this bastion is through the curtain, which ascends on the side of the hill, and is then covered by a demi- bastion, whose salient angle joins to a precipice and answers the upper flank of the flat bastion, as the lower flank of the same bastion does to the flank of the south bastion.

Gibraltar's South Front, Homann Moll Landeras, 1733.

William Test cross section of Charles V Wall, 1769.

View of the South Front of the Mountain of Gibraltar, William Test, 1779.

In his report dated 1770, Colonel William Green, the Chief Engineer was of the opinion that should the enemy breach the sea wall defences along the south and establish himself in full force upon any of our top levels of the Terra Firma…it might require greater Powers and Exertions, on our side, to defend the town as a citadel10

Using William Test’s earlier elevation plan (No. 4 in his Report); Green noted the imperfect and uncovered state of a great part of that [South] front. He therefore proposed to extend the covered way from the lower section of Charles V Wall from the salient angle of the western shoulder of the Flat Bastion all the way up to the cliff edge covered by the demi-bastion.

He also recommended a second project that was ‘evidently intended by the addition of the Ravelin to cover the Gateway and a lunette in the Place of Arms, between the Flat and Demi Bastions, to be susceptible, not only of a more formidable exclusive obstruction, but also of as great a protection to the Old Body of the Place, and as high a Defence as can be expected, from such an obsolete system of fortification…’11

As part of his third project, Green proposed the construction of a counterguard, which would link up with the ravelin. This counterguard would become part of what is now Ragged Staff Flank that extended right up to the grounds of the present Piccadilly Gardens. Neither the ravelin nor the glacis covering the approaches of the Flat Bastion and demi-bastion above were ever built. Details of Green’s proposal for the South Front were presented in his General Plan of the Fortification of the Town of Gibraltar drawn by William Test in 1778.  

General Plan of the Fortification of the Town of Gibraltar, William Green, 1778.

When the Great Siege of Gibraltar started a year later, a number of notable improvements had been added along the line wall – the most important of which had been the King’s Bastion. However, the South Front was woefully unprepared to withstand any form of frontal assault had the sea wall along the line wall to Rosia been breached.  Green reckoned that the unprotected curtain wall between the Flat Bastion and Demi-bastion on the east side could be breached in eight hours.12

Green rightfully concluded that the success of the garrison lay in the ability to hold the sea wall and fortifications along the western sea wall.

As part of the town’s defences should the sea wall be breached, Elliot ordered that twelve 18-pounder guns be placed on the Flat Bastion and three further guns on a barbette positioned at the head of the steps above the bastion.13

The Flat Bastion was to serve as a citadel to hold the centre of the South Front, which Green essential in establishing Charles V Wall into ‘a requisite state of strength and defence’.14 The citadel can clearly be seen in a watercolour by Lieutenant William Sandby Roberts ‘A View of the Grand Attack upon Gibraltar September 13th, 1782’.

1782 - View of Grand Attack Lt Sandy Roberts, 1785.

1782 - View of Grand Attack (detail of the Flat Bastion).

Lieutenant William Booth served in Gibraltar during the Great Siege describes the Charles V Wall and Flat Bastion as it stood in 1781:15

This Curtain is no more than 800 feet in length and has a large Flat Bastion constructed near the center, which makes the several flanks to be no more than 300 feet from each other; this Flat Bastion is made to augment the defence and protect the curtain from the high ground opposite to it, which obliged the Engineer to build high traverses of masonry which will prove very dangerous to those who are to defend within.

After the Great Siege, the guns at the Flat Bastion appear to have been removed. However, the Peninsular War and the approaching French Army prompted the commander of the Royal Engineers to advise the Governor, Sir Hew Dalrymple to re-establish the guns in the flanks to strengthen the defences of the Southport Gates. The Governor agreed, reporting that ‘Flat Bastion is also preparing to receive guns’.16

Original gate to the Flat Bastion, now sealed with debris.

By 1834, the armament had been reduced to four 12-pounders and two 12-pounder carronades.

In 1841, Major General Sir John Jones’s Overall Plan for the improvement of the defences was highly critical of the deteriorated state of defence of the entire South Front writing:17

I am led to consider the Southern Defences more seriously than perhaps may have been thought necessary for some time past, I therefore beg to submit to your judgement whether it may not be expedient to re-establish Batteries in the Flanks of the Flat and Demi-Bastions so as to bring on some defence on the South Front, as also obstructions in the approach to the Gates.

His recommendation was as follows:18

Item 4. To cover the Magazine and repair and restore the parapet and communications, and put the South Front into perfect order.

This front, built by Charles V of Spain, is of obsolete construction but the masonry being good, and the escarpe walls lofty, I should not have proposed more than the restoration of the decayed and damaged communications, had not a magazine, constructed a few years since on the left or upper flank of Flat Bastion, opened the escarpe wall, destroyed the flank defence and rendered imperative some additional walling as well to enclose the place and prevent the destruction of the building. The parapet of Flat Bastion requires to be re-instated and prepared for artillery and the communications to be made more easy, and some scarping is required along the left where the flank abuts against the rock face. The portion of the wall ascending the heights on the left of Prince Edward's Gate is exposed to view from top to bottom, and the Glacis and covered way along the flat ground on the right are so faulty and neglected as to be almost defenceless, and the former is used as a depot for guns, shot and shell, and being overshadowed by trees the whole exterior has a most unmilitary appearance.

The ground in front of the Line, however, being so closely plunged down upon by artillery on the flanking heights as to preclude the possibility of an enemy establishing himself on the Glacis, I cannot recommend any expense being incurred for their reform; and further, as the depot is conveniently placed for the movement of stores at Ragged Staff, I am unwilling to propose any interference with the existing arrangements of the Storekeeper, The trees and shrubs both on the Glacis and in the ditch are objectionable as impeding the view from the interior, and the dropping from the trees being found to cause serious damage to the shells I beg to submit the propriety of their being hewn down.

Following Jones’s recommendations, the entire left flank of the Flat Bastion was repaired. The works carried out can be seen in Captain S. Buckle’s photograph of the Flat Bastion from Eliott’s Monument collated by him during the late 1870’s.

Despite these works, on the 15th April 1859, Colonel Lefroy reported that the only armament on the Flat Bastion was four unserviceable 12-pounder and two 12-carronades, which had been there 'since Elliot's time'.19

A J. M . Carter colour print of Prince Edward's Gate from the Alameda dated to 1846 shows three of the four 12-pounders on the west flank of the bastion.

Prince Edward's Gate from the Alameda, J. M . Carter, 1846.

View from Elliot's Monument. Photographic views of Gibraltar, collected and arranged by Captain S Buckle RE.

Trafalgar Cemetery from Flat Bastion. Photographic views of Gibraltar, collected and arranged by Captain S Buckle RE.

The 1856 re-armament programme proposed to substitute two 6-pounders, two 3-pounders, two 24-carronades and four 8-inchhowitzers there but in 1863 only five 32 pounders were actually recorded, and none after this time.  

The Ordnance Survey map of 1861 offers the first detailed features within the Flat Bastion. It reveals four pivots and racers on the Right Flank, two smaller embrasures in the retired portion of the flank for carronades covering Prince Edward’s Gate, and five platforms on the next higher level on top of the first traverse, all of which face west. A communication tunnel provided access into the second level, which opened up inside the bastion right next to a magazine referred to as a Side Arm Shed. Another gate had been opened up on the wall connecting Flat Bastion Road to the third level where two buildings - a Shifting Room and a magazine had been erected. A tunnel appears to connect the Shifting Room and magazine, running underneath a blast wall.

War Department and Admiralty Properties, 1861-63 - The Flat Bastion.

Flat Bastion, 1861.

In 1873, the exposed front of the magazine was reinforced with a second layer of concrete as a precaution against the more powerful naval guns now being deployed by the new dreadnoughts of the time, especially the 100-ton guns of the Italian Navy. The thick casing on the magazine is similar to that encasing the Europa Tanks (old Casino), which was similarly reinforced during the same period. This extra layer and re-modelling of the entrances to the magazine can be seen in the Record Plan of the Flat Bastion Magazine. A deep ditch, some 10 feet wide was dug along the left flank, but it is not clear how far such a ditch extended. The plan also shows the Shifting Room having been converted into a cooperage.

The key stone above the magazine, dated to 1873, is therefore erected to commemorate the extension works and not the actual original magazine, which probably dates back to the at least as it is included in W. H. Smyth’s map of 1831.

The opening on the curtain wall, also mentioned by Jones was gated and much smaller than the present one. It would be widened when Flat Bastion Road was connected to Gardiner’s Road, probably at the end of the century, by which time Gardiner’s Battery had been decommissioned and the magazine abandoned. According to the site plan, the magazine could hold 3,652 barrels of gunpowder.

Flat Bastion Magazine Record Plan, 1873.

Flat Bastion Magazine keystone,1873.

The construction of Gardiner’s Road and the adjacent Gardiner’s Battery filled up the slopes along the left flank of the Flat Bastion to such an extent that parts of this section of wall is almost entirely covered by soil. Further private housing construction in the 1980’s has rendered part of the upper section actually lower than the road today. The increase of traffic along the old platform has increased the pressure on the medieval wall leading to the installation of buttress supports along the length of the platform.

By 1890, and probably much earlier, all guns within the Flat Bastion had been removed. The 1908 Ordnance Survey map shows that by this date a canteen for the Royal Engineers had been built on the first level to supplement the facilities for their barracks at Hargraves Parade. The NCO’s Mess was located on the ramp on the other side of the wall, which today houses Unite the Union offices. An iron bridge above Prince Edward’s Gate connected the barracks to the ramp next to Charles V Wall, which was now opened by a small gateway. The area above the canteen – the second level – was used as a recreation ground whilst a skittle alley was situated next to the wall on the first level. As a defensive position, the Flat Bastion was no longer considered as being of strategic value by the end of the 19th Century and most of the site had been abandoned before the first half of the 20th Century.

Old Royal Engineer's canteen.

In 1939, during construction of the Flat Bastion hospital shelter, the debris from the tunnelling was dipped over the third tier of the Flat Bastion down into the second level. This debris has covered the entire magazine and tunnel entrance below, which today is evidenced by the scree slope, which has left no more than a 20-feet (6m) drop from the top platform. Originally, the drop could have been as much as 50-feet (15m).

After World War II, most of the British service members were moved to the southern parts of the Rock under the 1946 Military Town Planning Scheme to provide housing for returning evacuees. The Engineers canteen was converted into civilian accommodation and a second storey was built much later. Most of these units are still being used today.

First gun platform.

Second gun platform.

Left hand flank of the Flat Bastion.

Right hand flank and scree slope.

Third platform and modern butresses to support the wall.

St. Jago's Bastion / Flat Bastion Image