1. Introduction

Defended both physically and through simple or sophisticated man-made constructions, the west Black Sea area contained a considerable number of fortified towns and forts either recorded in ancient sources or archaeologically identified.¹

2. Orgame-Argamum (Cape Dolojman)

The town² was founded in the third quarter of the 7th c. BC. The wall line shows a triangular layout. The contour of the town wall in the Archaic and Classical periods remains unknown, although traces have been detected southwest of the Late Roman enclosure wall. Presumably, an earthquake caused the collapse into the sea (today the Razelm Lake) of the eastern half of the town.

Detailed observations have been made only on the Late Roman town wall. The wall is 2.60m wide, made of rectangular schist ashlar set in regular courses (opus vittatum). The so-called flaring foundation of regular courses of schist blocks, bound with mortar, was built in steps towards the steep ravine to the lake. The precinct had rectangular bastions at regular intervals, while rectangular towers must have occupied parts of the west and of the south sides. An interior 6th c. court gate on the western side of the precinct wall conventionally called the ‘big gate’ was built of large-sized limestone ashlar. Another entrance (the ‘small gate’), a simple opening in the wall, is located on the south side.

The date of the Argamum late defence wall was established at the mid-6th c., during Justinian’s reign, as Procopius’ De Aedificiis mentions the works of rebuilding carried out at this town.

3. Histria (Istria)

The town of Histria³ was founded in 654 BC. The town wall had a long and complex development over the centuries.

3.1. The Archaic period

The territory of the Greek colony initially set on the coastal plain was divided into two main distinct areas, following an urban model known in the Greek colonial world. The highest quarter was chosen for the erection of the acropolis, possibly fortified at that time. The large civil area to the west was surrounded by a 2.5m or less wide precinct wall that encompassed a surface of ca. 50ha. It consisted of a mud-brick and wooden superstructure, plated with square limestone plaques set in the pseudo-isodomic system of masonry on a bed of limestone and green schist ashlars. Both fortified urban cores were seriously modified in the late 6th c. BC.

3.2. The Classical period

The demographic and economic progress attested in the Classical period required the building of a new 2.60m, green schist and limestone wide wall, oriented north-south, that enclosed ca. 35ha. It protected the main area of the town and was doubled by a 9m wide defensive ditch at 7-9m to the west of the wall. At least two gates pierced the precinct wall. This surrounding wall was destroyed in the second half of the 4th c. BC. The west edge of the plateau continued to be fortified with a wall similar to that of the archaic period, with minor repairs and a 3m wide ditch to the west.

3.3. The Hellenistic period

Two new defence walls were built in the Hellenistic period, one protecting the acropolis, and another, to the west, along the plateau edge, roughly surrounding the same large area as in the Classical period.

The acropolis' 4.50m wide precinct wall encompassed ca. 9ha. The new layout of the defence wall was a continuous line broken at spots which met the need for curtain towers. This wall consists of two trunks each built of well-chiselled large-sized stone ashlars set alternatively on edge and width and bounded with clay and schist boulders. In the late 4th or in the early 3rd c. BC the plateau edge was surrounded by a new 2.20m wide enclosure wall built of schist ashlars bound with earth and mud-bricks set in a rectangular moulds superstructure. The two double precincts ensured the town protection until the late 1st c. AD.

3.4. The early Roman period

The economic prosperity as well as the demographic and urban development under the 1st c. A. D. Roman administration necessitated the reshuffling of the structure and layout of the entire occupied area. A new town wall was built by the late 1st – early 2nd c. AD, which expanded considerably the activity on the large sandy plateau to the west. It encompassed a large area of ca. 30ha and cut the plateau roughly on a north-south direction. The new precinct, built in opus caementicium of green schist ashlars set in regular horizontal courses bounded with mortar, was 1.80-1.90m wide and set on a ca. 2.10m deep socle-like foundation. The wall had two gates and interior bastions and rectangular towers built at regular intervals. The south gate was flanked by two protruding rectangular towers. The town wall seems to have suffered some damage in the second half of the 2nd c., probably during the Marcommanic wars. Repair works implemented in a less careful technique were identified at some sections of the wall. In the mid-3rd c. Histria was severely damaged, a fact that rendered indispensable the construction of a new surrounding wall from the outset.

3.5. The late Roman period

The new town wall enclosed a much smaller area compared to the previous ones, which resulted from the intentional abandonment of a large zone on the west plateau. The new precinct was built in several phases in the second half of the 3rd c., beginning during Probus’ reign. A Tetrarchic inscription mentions important repairs and rebuilding.

The new 2.10-2.60m thick precinct enclosure consisted of a straight wall line built in opus quadratum of large rectangular ashlars and reused material of the 1st-3rd c. The excavations yielded evidence of 8 bastions and 6 towers that divided the west front line in ten curtain walls. There have been identified five main building phases (A-E), dated between the late 3rd and the late 6th c. In its final layout the town wall had six gates, of which the most important was the so-called ‘big gate’ flanked by two large bastions and two towers. The precinct had two earthen walls and ditches as adjacent elements of fortification.

4. Ovidiu

The 53 x 41m fort of Ovidiu⁴ is of the quadriburgium type, built in the late 3rd –early 4th c. and massively rebuilt in the 6th c. Four phases of building and repair were identified. It included two inland rounded towers and two square towers towards the sea.

5. Tomis (Constanta)

The overlapping modern city⁵ remains the major obstacle for extensive research, especially on the interior structures and on the evolution of the ancient town defence wall.

A mid-1st c. BC. decree issued by the Tomis town council alludes to the precinct wall (περίβολος της πύλεως). This seems to have been the Tomis Hellenistic enclosure wall, of which Ovidius speaks in the early 1st c. AD. It encompassed over 17ha of the present day Constanta Peninsula.

A new enclosure wall, whose traces are not yet identified, must have been built in the 1st or in the early 2nd c. It seems to have considerably extended the inhabited area of the Constanta Peninsula and defended the town only from land. An inscription of the second half of the 2nd c. speaks about repairs of short sections of the wall, probably during the reign of Marcus Aurelius, by public executives (αστυνόμοι) and funded by their own financial resources.

As the capital of the recently established imperial province of Scythia, at the end of the 3rd c., Tomis was surrounded by a new 3m thick, solid and far more extensive enclosure wall. An inscription dated between 285-292 shows that the main gate of the city was built under the direct supervision of the province’s governor, C. Aurelius Firminianus. Four monumental gates of the city are known to us. The Tomis urban surface was significantly enlarged to ca. 60 ha.

During Anastasius’ or Justinian’s reign the town's size was again significantly extended to the west, given an additional 10 ha. space. Wealthy individuals, like Alexandros and Bassos, substantially contributed to the repair or rather to the enlargement of the city defence wall. Professional guilds, like that of the butchers (μακελαρίων), also supported the repair of some segments of the same city wall with important funds. Procopius (De Aedif. IV 11) also confirms building interventions made by the state. A preserved inscription thanks God for ‘the rebuilt city’. The 6th c. wall seems to have been in use throughout the 7th c.

6. Callatis (Mangalia)

At Callatis,⁶ part of the sea and the modern town of Mangalia overlap considerably the ancient site. Three main phases of the ancient town wall were identified on its north, west and south sides.

Callatis seems to have been surrounded by a 3.75m thick defence wall built in large rectangular, well-chiselled limestone ashlars in the mid-4th c. B. C. In some marshy places, the entire construction was set on wooden beams forming a bed-like grid. Small drainage holes were opened from place to place.

A 1st c. AD Callatian inscription records the partial reconstruction of the enclosure wall at that date. It could have been in function until the Costobocae invasion in 170. Shortly after this date it was replaced by a new defence wall which overlapped almost entirely the previous structure. An inscription dated to 172 AD records the governor of Moesia Inferior, Valerius Bradua, under whose auspice the new town wall was built.

A new, 3.10 – 3.40m thick surrounding wall was built in the late 3rd c. It enclosed a space of ca. 13ha (370 x 420 x ca. 120m) although the submerged parts of the town could have conferred a larger surface to the fortified area. Rectangular towers were raised at spots along the precinct wall. A gateway on the west side was flanked by two big towers, while a smaller gate was placed on the south side. The town wall in this configuration lasted until the late 6th or the early 7th c.

7. Carum Portus (Cape Shabla)

The visible ruins of Carum Portus⁷ belong to the late Roman period. They have two main components: the port basin, surrounded at its north, east and south by three embankments with passages for the ships, and a stone and mortar trapezoidal fort with a round tower in the northwest corner. Archaeological investigations yielded traces of the Classical and Hellenistic periods (5th -1st c. BC) through the Early Imperial (1st -3rd c.) and Late Roman times (4th -6th c.).

8. Tirissis-Acres (Cape Caliacra)

The place⁸ had an excellent natural defence. Three successive north-south lines of fortification barred access from the land.

The first phase of the wall dates to the mid-4th c. BC. It encompassed the easternmost area of the promontory containing a five-sided fort of irregular layout with a central tower and a court–like gate. Another tower lies at the southwest corner.

In the 1st c. AD the wall had a second building phase, during which the gate was built in its final form.

In the third (mid-3rd c.) and fourth phases (first half of the 4th c.), new building interventions changed the wall layout radically, turning the fort into the citadel of the town. An inscription dating to 341-342 points out the important works of fortification carried out.

In its fifth and last phase (late 5th to early 6th c.), the wall of Tirissis did not undergo any serious transformations. The tower was heightened and the gate was narrowed.

9. Dionysopolis (Balcic)

The town⁹ was founded in the late 6th c. BC. Almost nothing is known about the existence or layout of the Dionysopolis enclosure wall in the Classical or the early Hellenistic period. Most of the modern town covers the ancient structures. The acropolis to the north of the town could have been fortified. Whether the new town defence wall was built in the 2nd c. BC. or earlier, given the political circumstances of that time, is still a matter of debate. In the Late Hellenistic and Early Roman periods (2nd c. BC.-2nd c. AD.), the terrain seems to have imposed a broken-like rectangle enclosure wall, which survived until the mid-2nd c. AD.

A new defence wall was built in the late 3rd and early 4th c., enclosing an area of ca. 36 ha. A succession of square and rectangular towers are noticeable, some with a pointed front on the most exposed northwest side, a configuration which is typical for the late 5th c., and some hoof-shaped on the north side.

10. Odessus (Varna)

Odessus¹⁰ was founded in the second half of the 6th c. BC. The modern town, superimposed over the ancient one, rendered archaeological research extremely difficult. An enclosure wall of the Classical period must have existed here, too. Traces of it seem to have been partially identified on the Kniaz Boris I and Archimandrit Filaret streets, from where it ran eastward and then turned towards the south, where it disappears under the modern structures. Its line towards the south and the west remains unknown.

11. Messembria (Nessebar)

The town¹¹ was founded in the early 5th c. BC. On the basis of the town wall's building technique three main phases of construction have been identified, dating from the 5th to the 1st c. BC.

In the first phase (late 5th – early 4th c. BC), rectangular but irregular stone ashlars were used as the main material for the wall construction.

Around the mid-4th c. BC, the wall went through a second phase, when it was repaired with regular rectangular stone blocks of different size in the pseudo-isodomic technique.

The third phase, dating to the Late Hellenistic (2nd -1st c. BC) and the Early Roman (1st c. AD) period was marked by the use of regular rectangular stone ashlars arranged in the isodomic technique, known also as the Binder-Laufer technique. However, a considerable part of the Late Hellenistic and Early Roman wall remained in use until the Late Roman period, when a new precinct wall was built. This wall is believed to have been utterly destroyed by a powerful earthquake in the mid-5th c.

In the fourth phase, from the mid-5th to the mid-6th c., systematic and massive construction interventions took place during Anastasius I reign. Repairs during Justinian's reign are evident on pavement bricks bearing the stamp 'Ιουστινιανού του Φιλοκτίστου'. There were several small gates and the main gate was flanked by pentagonal pointed front towers.

12. Apollonia (Sozopol)

Apollonia¹² was founded in 611 BC. The Archaic precinct wall was identified on the Kraibrezhna Street no. 61-63, facing the Kirik Island. A segment of the 5th c. BC town wall was excavated along the high, steep sea shore on the Viatarna Melnica Street. The enclosure wall of the Classical period seems to have been quite imposing in height and mass, enough to impress a military tactician like Aeneas Tacticus in the 4th c.

13. Salmydessos (Kiyiköy)

Salmydessos¹³ has natural defence towards the sea, laid on a rocky promontory protruding some 50m into the Black Sea, while towards the west there is a gentle slope open to a fertile plain ahead. There have been no systematic excavations of the town. A brick wall with a simple gate blocked access to the promontory from the west. The wall in its present state of conservation dates to the Late Roman-Early Byzantine era. The last surveys conducted in the area are suggestive of a date around the 5th or the 4th c. BC for the wall gate.