Fortress of St. Nikolas is a naval defensive fortress located on the islet of Ljuljevac, at the entrance to the channel of St. Ante near Šibenik. From July 9, 2017, the fortress of St. Nikolas, along with the defense system of the city of Zadar, is inscribed on the UNESCO World Heritage List, together with other fortifications called "Venetian fortifications from the 15th to the 17th century".
Fortress of St. Nikolas was built in the middle of the
16th century at the entrance to the channel of St. Ante, a narrow
sea passage leading to Šibenik. It is located on the south side of
the canal, on a small island, and is connected to the mainland by a
narrow path in the south. Its northern side is protruding towards
the opposite side of the canal, thus making control of the sea
routes of the area. Not far from the site of today's fort before it
was built, in the Middle Ages, there were two smaller towers between
which a chain was crucified to prevent unwanted ships from entering
the canal. After the construction of the fort, they were demolished.
The reason for the construction of the fortress of St. Nikolas was
the fall of the town of Skradin under the onslaught of the Turks in
1522. The conquest of Skradin provided the Turks with a favorable
position for establishing a maritime connection with the interior of
the already conquered territory, which was especially important for
them for the trade and export of raw materials. If their plan was
realized, the city and port of Šibenik would be endangered, and for
one of the strategically most important cities on the Adriatic
coast, this was not permissible. The port of the city itself was as
safe as possible, and the only entrance to the city was through the
narrow canal of St. Ante, so the place of the new fort imposed
itself. Šibenik additionally asked for help from the Venetian
Republic, which agreed, bearing in mind the importance of the city
and believing that those who hold Šibenik hold most of that part of
Although the proposal for the construction of the fort existed as early as 1524, the construction of the fort of St. Nikolas started when two prominent military engineers came to Dalmatia - the elder Michele and his nephew Giangirolamo, both from the Sanmichelli family. Allegedly, Giangirolamo made all the necessary plans that included the improvement of the already existing fortification system, but also the construction of new defensive fortifications. For the construction of the fortress of St. Nicholas in the channel of St. Ante Giangirolamo suggested the islet of Ljuljevac. The new plans for improved fortifications were immediately accepted by the Venetian authorities, and as the priority was the defense of the city from the sea, the works on the fortress of St. Nicholas began the same in 1540.
There was already a Benedictine monastery on the islet of Ljuljevac, which was demolished due to new construction. It was necessary to demolish the monastery church of St. Nicholas, and was replaced by a new one in the form of a chapel on the northwestern part of the fort terrace. The description of the fort is given by Giovani Battista Giustiani after the completion of construction in 1553. It mentions the circular part of the fort, which Sanmicheli himself calls the torion, and it is a small square where the chapel is located, probably on the site of the former church. The fort itself occupied most of the islet, and was built on a ridge and partly exploits the living rock. Giangirolamo designed it as a solid and secure triangle-shaped fortress with three prominent defensive bastions. It is built of several types of materials, so the lower zone of the fort is built of stone (parts below sea level and just above it), while above comes a part made of brick, which is common at the time of the fort, but unusual for Dalmatia. The bricks are known to have been delivered from the Veneto, which is proof that the builder of the fort itself, as well as the material he would use for this purpose, was important. Also for practical reasons the use of brick was probable as it absorbs stone cannon grenades very well. Inside, a larger amount of tufa can be seen, which is used to build the lower zone of the rim of the pan, as well as the vaults of most of the cannon openings. The living rock of the islet itself, carved in places and used in the structure of the building, is also important for the strength of the fort.
Perhaps the most interesting part of the fort is its shape itself. In general, triangle-shaped fortifications were rare at that time in Croatia, as well as in Europe. Nevertheless, such a form is found in Italy - the fortress Sarzanelo in Italy (1493), as well as Ostia near Rome (1482), while the triangular shape in Croatia occurs, for example, at the fortress in Sisak (1544). Šibenik, on the other hand, differs from them because it does not have a prominent tower. Also the height of the cortina, semi-bastion and torion is the same which makes the whole fort seem like a unique space. It is possible and most probable that the shape of the fortress of St. Nikola was influenced by the shape and amount of space on the islet of Ljuljevac. Likewise, given that this is a Renaissance period that is prone to basic geometric bodies and figures, an explanation of the triangle can be found in this as well. We should not forget about the economy and speed of construction, so the triangle is imposed as the simplest form of closing the space.
It is also interesting to note that the fort never actually
fulfilled its function because it was never active in combat or
defense. Sources convey a kind of anecdote of the first and only
attempt at defense when they wanted to shoot at the ships of the
Spanish Army near Zlarin. Allegedly, the fired bullet fell only a
few meters from the fortress because the wooden pedestal of the
cannon simply fell apart due to the high humidity. It is comforting,
therefore, that the fort from the sea seemed so powerful that no one
dared to approach it. This is, after all, the main task of such
fortifications - to scare and disperse possible attackers. Yet,
although it did not perform its primary function, the fort was
militarily organized from the beginning. Thus, in the already
mentioned Giovani's description, the organization of forces on it is
also mentioned. It is known from it that the crew of the fortress
consisted of 25 soldiers and five artillerymen. At their head was a
castellan, regularly elected from the ranks of the Venetian nobility
for a term of two years. During his term of office he was not
allowed to leave the fort under threat of the death penalty, and his
duty was in fact political, while the military commander called
himself a captain.
Today's appearance of the fort is very similar to that of that time, and although the practice of construction involved some changes and improvisations, it is believed to follow the original plan and idea. However, there have been some changes over time. Thus, already at that time, under Venetian rule, there was a occasional change in height on the terrace of the fort. During the 19th century, cannon barrels were replaced, which required additional changes, and new openings were made. In the 20th century, on the terrace of the fort, a traffic light station was built to regulate traffic through the Sv. Ante. For this reason, some buildings inside the fort were demolished, and all that has remained to this day is slowly decaying because the fort has lost its original function. Also in the interwar period, additional interventions were carried out such as piercing new cannon openings that damaged the vaults. The sources state that the Conservation entered the fort only in 1979, and the current situation is also transmitted. From the description, it is learned that the fort is in ruins, overgrown with uncontrolled vegetation growth, and that the moisture has contributed a lot to the poor condition. Most of the conservation work was done before the war because there was not enough money later. Thus, all the necessary repairs were carried out and all conservation research was completed. Two years ago, articles in the media reappeared about the dilapidated condition of the fortress and the need for urgent intervention and reconstruction, and even (quality) conversion, all for the purpose of preservation. museum to an elite casino, only shows how many professions, but also society do not yet see the seriousness, nor find a way out of the situation.
The appearance of the fort
Floor plan analysis
The basic floor plan of the fortress of St. Nicholas is a triangle. A rondelle was set towards the open sea, while opposite it, towards Šibenik, two half-bastions were set up. The semi-bastions are elongated, and they communicate with each other and with the rondelle by means of cortins. The shorter sides of the half-bastion, the ones with which they "look" at each other, are strongly retracted and create small ears, according to the curtain that connects them. There is a noticeable difference in the shape of the semi-bastion. Thus their length is unequal, and the roundness of their tops is different. This was most probably conditioned by the shape of the islet and the very living rock over which the fort was erected. Probably the western half-bastion is of an ideal planned shape. Its greater elongation can also be explained by the fact that it is the first to be approached from the sea, so the longer the wall, the greater the number of openings for cannons. Opposite the semi-bastions is a roundel of semicircular cross-section. Deviations from the ideal cross-section are also noticed, so that the eastern side of the roundel is partially flattened, which is again explained by the shape of the islet. The rondel also has indented ends of the semicircle and ends with ears. The ground plan of the lower level shows that its interior is somewhat filled with a wall dissolved by a kind of niche that extends like a continuation of the masonry from the center of the fort and reaches to the middle of the roundel. Because it follows its shape, it too is elongated and rounded, and is surrounded by a barrel-vaulted passage. The passage is spacious, and communicates directly with the five casemates, wider openings in the wall in which the cannons are housed. The passage from the rondelle continues directly along the western cortina, gradually widening towards the semi-bastion. Along the wall of the western curtain, five rhythmically arranged cannon openings can also be seen, almost at sea level. In contrast, the communication of the rondelles with the eastern cortina is somewhat more complex. There is no direct passage into it, but it is accessed by a smaller passage from the western curtain. The passage that follows the east curtain is not as clearly laid along the walls and does not follow the curtain like the one on the west side. Also here, the cannon openings are not symmetrically distributed, and there are fewer of them - only two. The larger opening hidden behind the ear of the rondelle is actually the entrance to the fort itself. The entrance was from the sea, and since the entrance was elevated, there was an access structure and a bridge that led to the fort through a representative Renaissance portal. The lower level floor plans also indicate sperons, partition walls placed transversely within the tops of the half-bastion, and together with the infill they further strengthened the foundations of the fort (such as buttresses). They occur in the smallest cortina, between the semi-bastions at the very southern end of the fort. Although most of the lower level was reinforced with infill, a trapezoidal space was left in the center between the cortins, and sources assume that there was, among other things, a cistern. The floor plan of the upper level is somewhat different. A unique open space is observed whose trapezoidal middle is filled with smaller objects, and their arrangement also follows this shape. It should be noted here that the interiors are barrel-vaulted, while there is a terrace above them. The rondel retains its shape, the five cannon openings remain here as well, and the space that fills it is now larger. Here, however, it should be emphasized that what is read in the ground plan as an opening is in fact a narrow opening between the casemates, here in the form of small fortified houses that continue to the walls and in which the cannons are located. The casemates are located along the cortins on both levels, and are also circularly arranged along the walls of the roundels. In front of the casemates of the upper level in the ground plan, the indicated rectangular skylights can be seen, openings in the vaults of the internal casemates, which also served for ventilation from gunpowder gases during cannon fire. The central part is filled with objects in the interior - three rectangular rooms, one semicircular under the torion and a corridor that connects them, all barrel-shaped arches and grouped so as to leave space along the curtains on both sides equally. At this level, there are as many cannon openings as there are casemates, and they continue along the walls of the half-bastion, so the west side now has eight, and the east side has five. Along the very edge of the shortest curtain at the southern end of the fort, two roof constructions with an opening in the center can be seen - the cistern drains on the lower level.
Exterior appearance of the fort
As already mentioned, the portal of the fort is hidden on the east curtain, behind the ear of the rondel. The entrance is framed by a renaissance portal on which local masters, Dujam from Split and Frano Dismanić from Šibenik, also worked. The portal is rectangular in shape, and the entrance itself is in the middle and is semicircular. The entire portal is "covered" with rustic, a visual sign of a representative and defensive role. Thus, the entrance is accentuated by the rustic that follows the arch, and only the top of the arch is further emphasized by the sculpture. The rustic is also transferred to three-quarter pillars in a variation of the Doric order flanking the entrance, while at the outer ends, at the same level as the three-quarter pillars, there are pilasters. Both the pillars and the pilasters are prominent in relation to the entrance itself and carry the beams. Triglyphs and decorated metopes alternate along the length of the frieze, and the portal is concluded by a prominent wreath on which once stood a lion as a symbol of the Venetian Republic. Unfortunately, the lion was damaged. It was later carved again by Emperor Francis I, but was also destroyed by soldiers of the Kingdom of Yugoslavia in 1926, when it was smashed and thrown into the sea. Observed from the sea, the fort does not show particularly noticeable details. Imagining approaching it from the sea, the first thing we would see would be a rondelle and a western curtain. Almost at sea level, large openings for cannons can be seen, while from the highest level the space is monitored by casemates. This arrangement was considered ideal by Giangirolamo because the lower-level cannons could directly hit the sides of the approaching ships, while the cannons in the upper-level casemates destroyed their masts. Rondel almost stands in the sea, natural rocks can be seen near the cortina, while in the very south, in front of the semi-bastion, there is the rest of the islet that connects the fort with the mainland. The exterior of the fort is not rich in details or decorative or architectural analysis, but the only articulation is a narrow profile to two thirds of the height of the fort, which visually separates the lower from the upper horizontal floor.
Taking into account the time of origin and shape, the fortress of St. Nikolas is connected, among others, with the fortifications in Saranzell in Italy and Sisak in Croatia, and even more with the Venetian group of fortifications that defended the entrance to the Lagoon. Nikolas is a bit more complicated. It differs from the already mentioned fortifications by a combination of roundels and elongated half-bastions. The use of the semicircular shape of the rondelle as the most prominent point at that time was avoided in defensive construction because it left the front space indefensible, but at Sv. Nicholas is explained by two reasons. The already mentioned reason why the absence of rock and land in front of the rondelle does not cause fear that the enemies will reach the bottom of its walls and attack, is added the possibility of an ideal arrangement of cannons on both levels. There is also innovation in the very combination of rondels, cortins and semi-bastions. Namely, the masonry of the rondelle does not continue directly on the cortina, but is connected to them by retracted ears cathartic for polygonal towers, and the arches located in them control the walls of the western and eastern cortina. Nevertheless, the greatest innovation occurs in the organization of the southern part of the fort, where for the first time in all Venetian construction tenals appear. It is formed by two semi-bastions connected by cortina, and the solution is also called pliers. Analyzing the fort, we see a new combination of already existing elements, which is why it is mentioned in the sources as a kind of bridge within the morphology of defensive architecture between (form and typology) past and future. As then an important city on the Adriatic, and with a new role of defense against the Turks, Šibenik had to get a fortress like St. Nikolas, which is solid and up to date with the trends and construction of that time. Probably added to the distance from the center of the Venetian Republic, which gave Giangirolamo Sanmichele "freer hands" in planning the fort, and the result of innovation and one of the most unusual examples of Venetian defense architecture.