Fort St Angelo during the Great Siege

If the fortified city of Birgu provided  the Hospitaller knights with their main front line defence in their island stronghold of Malta,

then the keep of the Order’s defences inside the Grand Harbour during the Great Siege of 1565 was the Castrum Maris or Fort St Angelo, as it was called by the knights. This old sea-castle was situated at the tip of the Birgu peninsula and was a remnant from medieval times.  It had been the only work of fortification available to the knights of the Order of St John when they arrived in Malta in 1530 and, for nearly a decade, until the enclosure of the nearby town with bastioned ramparts, the old castle served both as the Order’s main stronghold and also as the seat of the Grand Master and his retinue. Its location allowed it to serve as a sentinel, watching over the entrance to the harbour and protecting the anchorages in the nearby creeks.

By 1565 the Castrum Maris had changed very little from the way the knights had found it in 1530.  It was intrinsically still the same medieval structure inherited from the De Nava castellans except for a few alterations which had been undertaken in the course of 1530s and early 1540s and which were designed to provide the old castle with some basic form of artillery defences along its land front.  D’Aleccio’s print of Fort St Angelo during the siege effectively sums up the situation when it depicts a bastion and cavalier crudely grafted onto a turreted medieval trace of walls.  The illustration also reveals a moat along the bastioned front.  This was the first significant intervention on the castle made by the Hospitallers and was aimed to isolate the stronghold from the mainland, thereby making it less accessible and reducing the danger of a landward assault while at the same time effectively countering any threat from mining. The construction of the moat involved the conversion of la Tagliata, that is the dry ditch of the old sea-castle, into a sea-filled cutting.  Giacomo Bosio, the Order’s historian, claims that the ditch between the Birgu and the castrum had been excavated to around sea level by 1536 but it was eventually deepened further in subsequent years and could adequately shelter galleys in 1565. Concurrently with the excavation of the ditch, the knights also undertook the construction of new terrepleined ramparts flanking it and facing the town.

These works progressed slowly but by 1565 they had come to constitute a new land front consisting of a small arrow-shaped bastion grafted onto an adjoining short stretch of terrepleined rampart, the whole commanded by a towering cavalier.  The design of the new bastioned front, however, was not particularly well-developed. The main problem lay in the narrowness of the neck of ground on which the castle was built for this did not allow for a fully fledged defensive line with mutually flanking bastions.  As a result of these restrictions, only one bastion was built, for the construction of a second bulwark meant that this could only be erected in the sea – an undertaking which, in the circumstances prevailing at the time, involved too great a cost. Enfilading fire along the front, therefore, was only possible in one direction. Not surprisingly, the new works came in for much criticism from the Italian military engineer Antonio Ferramolino when he visited the island in 1540.

The bastion itself, known as D’Homedes bastion, is typical of the first generation Italian style of bastions. It was the first gunpowder bastion to be erected in Malta.  Typical of the early Italian bastions, it is relatively small, high, and exposed and has an acute-angled salient with pronounced orillions that in plan resembles an arrowhead.  Originally it seems to have had square orillions for it is frequently depicted as such in old maps of the harbour and also because contemporary bastions erected at Mdina, one of which is likewise known as D’Homedes bastion, have square rather than rounded orillions. Unfortunately no original plans of this bastion have turned up, making it difficult to establish whether the present configuration is authentic or the product of later interventions.  Various factors tend to suggest that the bastion underwent considerable internal and external modifications throughout the course of the centuries particularly when it was adapted to serve as a powder magazine in the seventeenth century. The left flank of the bastion was reinforced with the grafting of a thick masonry revetment that practically obscured the orillion and hid two sea-level embrasures.  Likewise, the escutcheons of Grand Masters L’Isle Adam, Del Ponte, and Saint Jaille known to have been placed by the knight Jaconio Pellequin on the right face of the bastion are now to be found, together with a fourth, on the left face.

A solidly built cavalier stands to the rear of D’Homedes Bastion. This towering artillery platform was designed by Ferramolino and begun in 1542.  It was not built for the immediate defence of the sea-castle but mostly as a counter-bombardment position designed to oppose enemy siege positions planted on the surrounding and overlooking heights of Santa Margherita and the Sciberras peninsula.  Sentinels standing on the roof of the cavalier could also keep a watch on the entrance to Marsamxett harbour on the other side of the Sciberras peninsula. The construction of the cavalier progressed very slowly and it was not until January 1547 that the Council finally entrusted the completion of the structure in the hands of the knights Fra Goudisalvo Guiral and Fra Carlo Durre.  Raised on three barrel-vaulted casemates, it is an impressively solid and stable artillery platform that must have been capable of mounting many pieces of cannon and various culverins. It is shown as having a parapet fitted with embrasures in most eighteenth century plans. D’Aleccio’s prints, however, only shows a single large cannon positioned on the cavalier and firing en barbette.

The completion of both bastion and cavalier absorbed most of the attention of the knights in the years leading up to the siege. There were, nonetheless, other minor though significant defensive measures which were adopted to strengthen the defences of the castle. The threat of a Turkish incursion in 1541, for instance, had forced the knights to block the mouth of the creek between the castle and Isola Point with a barrier of boats leashed together. This operation had involved a great deal of preparation and so in 1546 an iron chain was ordered from the arsenal of Venice to take the place of the floating barrier.  It was brought over to Malta on the timber transport vessel, the Contarina, and remained in use until 1564 when it was in turn replaced by a new chain just prior to the arrival of the Turkish Armada.

Another important feature was the so-called De Guiral Battery. This was a fleur d’eau battery built just prior to the siege at the tip of the peninsula and designed to protect the chain closing the mouth of the creek.  It seems that this battery was fashioned out of the rocky foreshore at the foot of the castle. Three of these embrasures, cut out in the rocky shore, are still visible and appear to belong to the original emplacement. Various eighteenth century plans show a rectangular De Guiral battery with masonry embrasures. Named after the Hospitaller knight Francesco de Guiral, who was placed in charge of the battery together with the crew of his galley just prior to the arrival of the Turkish armada, the position was, initially, totally detached from the old medieval castle to its rear. It only came to form part of Fort St Angelo following Don Carlos de Grunenburgh’s reconstruction of the fort in the late 1680s. The architect of the original idea for the construction of the battery is not recorded. Various engineers were operating in Malta prior to 1565, although most of these were, in effect, simply implementing the recommendations made by the renowned Baldassere Lanci in 1562. The sea-level batteries along the shore of the Castrum Maris (there was a second battery at the foot of D’Homedes Bastion nearthe moat of Fort St Angelo – see D’Aleccio)  subscribe to the notions of entrenchments and ritirate that were strongly advocated by Lanci in his instructions to Grand Master Jean de Valette, many of which, like the entrenchment at the Post of Castile in Birgu, were actually constructed.

The De Guiral Battery was to prove to be one of the most effective works of fortification ever built by the knights of St John, for it served to defeat, single-handedly, a major Turkish seaborne assault on the neighbouring fortress of Senglea. Either because it was very well concealed (although judging by D’Aleccio’s illustrations -see above - it was surely not hidden from view) or because the Turks had seriously under-estimated its firepower, the Ottoman commanders somehow failed to take into account the effect of the battery on their assault of 15 August 1565.  A timely salvo fired from five pieces inside De Guiral’s Battery ripped violently through a flotilla of large boats packed with Turkish troops as they sought to close in on the Spur of Senglea, shredding them to pieces. Nine of the largest boats were sunk outright, sending some 800 Janissaries and Levantines to the bottom of the sea, and, in the process, saving the hard-pressed garrison of Senglea from a terrible fate.

In 1565 Fort St Angelo still relied on its medieval walls and towers for most of its protection. The exact shape and layout of these medieval elements are not well understood given the lack of available information and the dearth of surviving medieval architectural elements.  Most of the ancient structures were replaced by the additions and alterations carried out in the course of the closing decades of the seventeenth century.  The only significant features dating from the earlier part of the castle’s history are to be found in the upper part of the fort that form part of the magisterial compound.  Even these few elements, however, were heavily altered during the Hospitaller occupation and constitute little more than isolated remnants. Most of what is known about the old castle, therefore, has been culled from sparse medieval documentation and a few plans. One important source of information on the medieval castrum maris is to be found in a scale stone model commissioned by Grunenburgh to illustrate the layout of his proposed redesign of the fort which he presented to the Order’s Council in 1687.

It would appear that the pre-1530 medieval castle consisted basically of an inner and outer ward.  The inner castrum, and possibly the oldest part of the stronghold, the castro interiore, retro ecclesia Sancti Maria, formed a triangular enclosure in which stood the castellan’s residence. This corresponded roughly with the perimeter now enveloping the highest part of the promontory and enclosing the magisterial residence and St Anne’s chapel.  This inner enceinte was fortified with a number of wall-towers of which at least two were rounded and were sited on the western side overlooking Senglea.  One of these two towers has survived and reveals the use of large ashlar masonry blocks, probably re-utilised classical masonry, in its lower courses.  It was well-built with rusticated masonry, parts of which have been recently unearthed, and shows that the castle’s towers were not much unlike those found on Swabian strongholds in nearby Sicily.  The second rounded wall-tower was located close to the chapel and appears to have been that which the Sicilian documents refer to as the ‘Tower of St Angelo’. This tower is known to have been repaired in 1517 with the use of some 130 cantuni (stone blocks), 30 capstones, and 900 salme of rubble.

The magistral palace that housed Grand Master Jean de Valette was built to accommodate L’Isle Adam in 1530 and had replaced the castellan’s residence,  parts of which, however, were retained and incorporated into the new building. The old hall was converted into an ‘aula major et nova’ and was being used for council meetings by February 1534 while a new annexe bearing the arms of L’Isle Adam seems to have been added to the south. Architectural evidence shows that the knights enveloped the original building within a stronger outer shell fitted with corner buttresses and the whole structure was given the form of a rectangular keep. At least on one side, to north, the original medieval building extended northwards towards the chapel and was cut short by these sixteenth century interventions. The small church of St Anne, close to the palace, became the magisterial chapel. This was fitted with a new side chapel within which L’Isle Adam was eventually buried in 1534. A dome (‘tolo’) is said to have been constructed by L’Isle Adam  close to the chapel in order to house the Order’s treasures.  The upper ward of the castle itself served by its own gateway, the foundations of which were unearthed during the course of restoration works.

It is even more difficult to discern the outline of what was the castle’s outer bailey.  The medieval documents speak of the ‘castro exteriore ante ecclesiam Sancti Angeli,’ which would place it on the north part of the peninsula. Evidence, however, shows that the walls of the outer ward stretched as far south as the present cavalier. Here, as Grunenburgh’s model clearly shows, the walls of the outer ward were designed to absorb the shock of an attack down the peninsula from the mainland.  When designing the cavalier, Ferramolino left standing a small medieval wall-tower and a short stretch of adjoining curtain that once formed part of this outer enclosure. The stone model also clearly shows this part of the medieval enceinte as having had a heavily sloping talus, a feature which is likewise attested by the documents where these refer to the building of a pronounced scarp in 1477.

The area within the outerward was occupied by a number of auxiliary buildings, including a tavern. One block was actually built onto the east flank of the bailey facing Kalkara.

Judging by Grunenburgh’s model, it appears that this row of buildings was imposed on the castle at a later, post-1530 date as it jars entirely with the stronghold’s medieval character.  These buildings, in all probability, appear to have been added by the knights in an attempt to improve the castle’s accommodation facilities so that it could house a larger garrison and retinue of knights. In all, these consisted of a row of seven blocks. They suffered considerable damage during the earthquake of 1693, for in August of that year the Commission of War ordered their demolition together with five rooms situated  along the ramp leading up to the castle from behind the gate near the chapel of St Mary.   A large number of  rock-hewn cisterns and granaries were to be found all over the castle.  Some of these were transformed into prison cells (‘guve’) and used to detain errant knights.

There was also a barbican which protected the main upward passage into the castle and an antemurale with towers and a gate situated down by the sea. This outer wall appears to have been truncated with the building of D’Homedes Bastion in 1536.  One document speaks of the bastion being built ‘davanti la porta del castello in questo Borgo.’  In 1523 a tower was erected over a gate of the castle under the superintendence of Antonio Fantino.  There also appears to have been some sort of casemated battery situated on the northern slope of the promontory just below the magistral palace and facing out to sea – a sort of ‘myne’ or covered battery of guns such as was built by the Hospitallers at Bodrum castle in the late fifteenth century.  It is not yet clear if this battery was a pre-Hospitaller structure or if it was added by the knights.  It is distinctly shown in all illustrations of the period up to the late seventeenth century when it was replaced by a new multi-tiered enceinte designed and built by the Flemish engineer Colonel Don Carlos de Grunenburgh.

Historians have yet to establish exactly at what point in time the castrum maris was dedicated to St Angelo. The castle is known to have had a chapel dedicated to this Saint as far backwards as 1274 but it is only during the Hospitaller period that the stronghold is referred to by such name. The first references to ‘Fort St Angelo’ are not met with until 19 July 1540, when the knight Claudius de Humblieres is documented to have been confined in the ‘Carcere Sti Angeli’.

As all veritable military outposts, Fort St Angelo also held a central armoury, a powder magazine, and a large powder factory. In many aspects, the castle, despite its obsolescence, served as the knights’ military headquarters. Its privileged position, on the highest ground at the tip of the Birgu peninsula gave it a certain command over the harbour enclave. Various batteries of guns were set up inside the castle, one of which was sited on top of the cavalier, and these were used to give supporting fire to the rest of the harbour defences, including Fort St Elmo.  The castle’s garrison, under the command of the Catalan knight Galceran Ros, also doubled up as the main reserve, and was frequently sent to the aid of threatened posts.


In reality, limited by its ancient ramparts, there was little that the old sea-castle could have offered in terms of effective resistance had it become the object of the Turkish assaults.  To the knights and their men, however, it represented a place of last resort. Physically, and psychologically, it was the keep of the Hospitaller position, the final refuge place so to speak, where, if all else were lost, some sort of safety and retreat could be found and a last desperate and heroic stand made.


Dr. Stephen C Spiteri PhD

MilitaryArchitecture.com (C)



Dr. Stephen C Spiteri PhD

Latest Articles








Date and Time to be 

announced soon


~ Additional Features ~