The Byzantine Acropolis was built on an ancient fortress that protected the city during the 7th and 6th BC century.
During the Byzantine era, the acropolis is mentioned in many chrysobula (imperial decrees) of the various Byzantine emperors as “Castle”. But over time, the word “castle” came to refer to the entire city. That’s why, until the beginning of our century, the people of Serres were called “Kastrinoi” (people of the castle) by the inhabitants of the surrounding villages. From the Frankish conquest onwards, the name for the Acropolis was “Kastelli”, which was preserved until the years of the Turkish occupation. The Turks called it “Bas Kule” (head tower), probably because of the large tower on the western side. The current name “KOULAS” (tower) originated from this Turkish name.
The Acropolis, during the Byzantine years, was surrounded by a strong wall with a spindle shape, which extended from the West to the East. Within its walls, it enclosed the various Byzantine buildings, usually the residences of the respective governors and other state officials. Also, in the Acropolis resided the castle guard appointed by the Byzantine authorities. A well-known castle guard is Leo the Azanite, who countersigned to a chrysobula, written during the first half of the 14th century.
The wall of the Acropolis, according to the Turkish traveler Evlias Celebis, had two gates, one of which was located on the eastern and the other on its western side, very close to the respective towers. Traces of the second gate can still be seen today near the large tower on the west side. High and strong towers strengthened the defensive power of the wall, of which only the strong and majestic western tower, known as “the King’s tower”, was saved with minimal damaged only in its highest part. It was built on an older building, probably a tower, which can be traced back to archaic times. The solid base of the eastern tower of Vasileos is 7 m high, 12.50 m wide and 16 m long. The second floor was built on top of the base and is smaller, 11 m wide and 12.50 m long. Today its height is approximately 6.50 m, while it originally reached 9 m with its ramparts. On this floor there is a long narrow archway last hall, the entrance of which is on the eastern side, where is the (staircase) that leads to the ramparts. Because the western side of the hill had a smooth slope, the external height of the tower, which today reaches 18m, would initially reach 20m with its ramparts.
This huge tower had a dual purpose. On the one hand, it protected the city that was next to it. On the other hand, it was the last point of defense in case the enemy occupied the rest of the Acropolis. This last point of defense necessarily exists in all Medieval Citadels, either in the form of a stronghold, or a small fortress, like the Eptapirgio in the Acropolis of Thessaloniki, or finally as an individual multi-story tower, like the Acropolis of Philippi.
The foundation of the Byzantine Acropolis dates back to the 9th century AD. It was then mentioned for the first time by historical sources that the Emperor Nikephoros Phokas built fortifications in the city of Serres. The Acropolis was luckier than the city wall because it was saved from terrible barbarian raids and catastrophe. Even in 1204 AD, when the city walls were completely destroyed, the Acropolis evaded destruction. However, with the submission of the city of Serres to the Turks in 1383, the abandonment and gradual ruin of the Acropolis began, because the Turks planned on destroying the castles, so that they would not become hotbeds of resistance in case of a revolutionary movement of the Greek slaves.
The emperor Vasileios II completed the triple wall fortification of Serres in 991 AD. The outer wall started from the Orestis tower of the Acropolis, went down to where today’s 3rd Gymnasium is located and from there it continued towards where the east side of the social security institution building is and ended up to where Ethnikis Antistaseos street is today. It continued towards the Old Hospital Facility, and then it ascended towards the Byzantine Temple of Saint Nicholas located on the Acropolis.
The second wall, only few parts of it are still surviving on the steep sides of the hill, was erected along three sides of the hill. The third wall, that had five towers, was on top of the Acropolis, around the area of the Periptero.
When the outer wall was occupied, the army, the women and children would go inside the second wall of the citadel and defend themselves from there. If the second wall was also taken, they resorted to the third on the top. By removing the movable wooden passages and stairs, they isolated the wall from any enemy access. There were large water reservoirs as well as camp and guard facilities inside the towers. The surviving tower was rebuilt several times on the old foundations.
In 1958, during the foundation of the Periptero, new findings were discovered. Specifically, in the location of the Periptero, an archaic tomb of a woman was discovered, which contained important gifts, but was quickly covered in order not to hinder further construction work. This tomb probably belonged to the 6th BC. century.
A few meters south-east of the periptero, the excavator revealed foundation remnants of an archaic building, made of tufa. As suggested by the archaic capitals found during the excavation work, the remnants probably belong to an ancient temple.
A grave was discovered around 100 meters northwest of the surviving tower, in which were found calcined human bones and a dark-colored, undecorated wine-shaped vase.
Fascinating the Emperors since the beginning of the Byzantine era, the city became an outpost of the freedom of the Byzantines, by getting strongly fortified with high and strong walls. After studying old blueprints, it is suggested that there were two enclosures of walls. One of the walls surrounded the old city (the “asty”), and the second divided the old city transversely and was intended to strengthen the defenses of the Acropolis in case the enemy occupied the lower part of the city.
The Byzantine wall had several gates leading out of the city. One of them, which was located very close to the current Byzantine Church of Saint Ioannis Prodromos, was called the “Royal Gate” because the royal family ascended to the Acropolis through it. The gate on the east side was called the “paraportion.” Southeast of the Church of St. Anthony and St. Marina was the “central gate” which the Turks called “Orta Kapou”. Ruins of a gate can be found on the western side of the wall, which in Turkish was called “kunluk kapu” (gate of the station), part of the gendarmerie station that once existed there. The entrance to the city was closed with chains at night. For this reason, the nearby church of Agios Athanasios was called in Turkish “Zinjirli-klise”, which translates to church of chains.
In 1345 AD, the King of Serbia, Stefanos Dusan, taking advantage of the strife during the civil war, conquered the city of Serres after a long siege. A remnant of the Serbian occupation is the great tower of the Acropolis, known as the tower of Orestes.
The tower of the king is well known to those who are involved in the medieval history of Macedonia, Greece, because of the two inscriptions written in tiles located on the western wall of the upper floor. They are written with blocks of bricks inserted into the wall and held together with plaster. Over time the plaster crumbled in many places and pieces of the plinths shifted or fell. That is why reading certain parts of the inscriptions is very difficult. As a result that we have different wordings of the inscriptions.
More interest was gathered for the large inscription on the right end. P. Papageorgiou proposed the reading: “Pyrgos augustou Vasileos on ektisen Oresti (Tower “Orestis” build by king Augustus)”. N. Veis: ” Pyrgos Augustou Elenis on ektisen Orestis (Tower “Orestes” built by Augustus Helen)”. Soloviev “Pyrgos STFOU Vasileos on ektisen Orestes” i.e. “Tower ST(E)F(A)NOU Vasileos on ektisen Orestes”. Academician Mr. Xyngopoulos in 1965 agreed with Soloviev’s opinion. However, the most likely reading seems to be “Pyrgos Andronikos Vasileos on ektisen Orestes”. Thus, we believe that the tower was built during the reign of Emperor Andronikos III, who is mentioned by Kantakouzenos in 1341 AD. He walled Amphipolis and Demir Isar and probably also the city of Serres. The double-headed eagle that can be seen on the top of the cap indicates the Byzantine origin of the tower.
At the north-eastern end of the Acropolis castle is the beautiful Byzantine church of Agios Nikolaos, which was restored and renewed in 1937 by 3 ladies from Serres.
The oldest information about the Temple can be found in a passage from Praktikos (1339-1342 AD) where there is a reference to the “tower of Agios Nikolaos”. Obviously, it is referring to the tower of the Acropolis, which was raised near the St. Nikolaos Holy Orthodox Church, where it got its name from. The second mention of the temple is in the travelogue of the Turkish traveler Evlias Celebis (17th century), who mentions that he saw a destroyed temple in the then deserted castle. It is certainly the church of St. Nikolaos Holy Orthodox Church, whose dereliction had just started at that time.
The French Capuchin Robert de Dreux, when he passed through the city of Serres in 1669, reports that he saw two ruined chapels on the castle. One of them was probably the church of St. Nikolaos Holy Orthodox Church. The French consul and traveler Cousinery, during his second visit to the city of Serres (1814) notes that he saw inside the castle the ruins of St. Nikolaos Holy Orthodox Church, in which several remains of frescoes were also preserved.
Architecturally speaking, St. Nikolaos Holy Orthodox Church is classified among the usual triangular monoclites with a dome. Essentially, it consisted of a central square covered by a dome, which rested on a free arch on its eastern side. Its other sides rested on shallow arches that opened through the thickness of the walls. On the west side of the square was attached another narrow oblong space, which formed the narthex.
Until 1926, several remnants of frescoes were preserved inside the church, such as the representation of the sacrament and Transmission of the Apostles, Jesus lying as a naked child (Lamb), the Angel holding a flabellum, the Bust of the Mother of God and the icon of Modestus of Jerusalem, who was blessing the people with his right hand and holding the Gospel with his left. In many parts of the temple, remains of jewelry can be found with the usual style and themes of the Palaeologian era.
On the eastern side of the church, under the two-lobed window of the arch is the entrance to the crypt. This crypt had a cemetery purpose, i.e. it was a burial place for the soldiers of the castle guard, who were killed or died in it due to illness or other causes. The cemetery character of the crypt of St. Nikolaos Holy Orthodox Church is confirmed by the few remains of graves and human bones found inside it.
According to the indications in the 1339-1342 AD Records, as well as the form of the church’s masonry, it can be concluded that the St. Nikolaos Holy Orthodox Church was built before the Serbian occupation, specifically during the first half of the 14th century (Paleologian era).