The fortifications of the Greek-Bulgarian frontier



After Balkan wars, the Greek Army Staff estimated that Bulgaria had the capability to strike Greece fast and effectively as it had a stronger army that could be mobilized and moved forward to the borders more swiftly on account of the terrain and the good condition of the transportat network. Moreover it was expected that if Greece and Turkey were engaged in military conflict, a Bulgarian attack would be imminent. It was as a result of these circumstances that the fortification of the Greco-Bulgarian border was decided upon, following an initiative of the director of Directorate A of the Army Staff Service, lt.col. Ioannes Metaxas. The construction of the fortifications was assigned to the Salonika Fortress Command with a special staff under the command of colonel (Eng) Eulampios Messalas.


The part of Macedonia east of the Mesta river is divided by the Struma river into two regions: central and eastern Macedonia. Eastern Macedonia was exposed to the Bulgarian attack, therefore the fortification of the frontier was of primary importance. However the finances of Greece were poor because its army had been doubled in size. The safety of the urban centres of eastern Macedonia (Drama, Serres) was of a vital importance, because if these towns were lost, this would mean the loss of the whole Eastern Macedonia. As a consequence, Salonika, which was a large military base, would be threatened. The only way to ensure the safety of these towns was to fortify the frontier.

The fortification of just one line was inadeguate because, if it were to break at one point, the entire region of eastern Macedonia would be placed under threat. Therefore a second interior line was necessary to contain an invasion. However it was realized that if the construction crews working on the fortifications were divided among two locations, it would take them too long to complete the plan. For this reason the main passes at the frontiers were fortified and of the interior line only Kavala, and the bay of Eleutherae, along with a few isolated interception works on the border. In this way eastern Macedonia was secured and the problem regarding the mobilization and the strategic concentration of the Greek force was resolved. The fortification by interception works were designed to withstand an enemy attack lasting no more than a few days. They were fortified enclosures, of a semi-permanent nature, affording all-round defence. Their garrison artillery should interdict some approaches to the enemy, while their infantry should secure local defence. Isolated forts flanked by smaller enclosures would deny the investment of the main fort and its envelopment.


The following forts were constructed on the Greco-Bulgarian border:

Rupel, 11 kilometres north of Siderokastro for the defence of the Siderokastro pass and to safeguard the Greek valley of the Struma river and Serres;

Phaia Petra, 28 kilometres north of Serres for the defence of the mountain passes that lead from the Bulgarian valley of the Struma and Ali Butush towards Serres and Siderokastro;

Perithori, 25 kilometres east of Phaia Petra for the defence of the approaches from the plateau of Kato Neurokopi to Serres;

Lisse, a twin of the Perithori Fort, for the defence of routes to the plateau of  Kato Neurokopi to Drama;

Tulumbar, 16 kilometres northeast of Drama, for the defence of the routes which converge from Rhodope mountain to the bridge of Papades village

Paranesti, near the railway bridge over the Mesta river, for the defence of the Korpyla defile.

Paradeisos, 20 kilometres north of the mouth of the Mesta river for defence from the direction of Xanthe.


Owing to a lack of means, the forts were not flanked by smaller permanent constructions, but with field fortifications that were built by the units stationed there. The fortifications of Kavala included fortified enclosures of the same type as the interception forts, and provided the capability of cross fire. The enclosures were complemented by smaller ones. Thus the entire line was strongly fortified, covering Kavala and the bay of Eleutherae. The area from the fort of Paradeisos to the mouth of the Mesta river was considered an obstacle for the enemy and so it was not fortified. The ridge of Kerkine mountain also remained unfortified. The fort of Dova Tepe (Kastanousa) east of Dojran lake was constructed for the defense of the passes and the protection of the railway line. The defensive position of Dysoron mountain (Krusha Balkan), east of the fort of Kastanousa, was not fortified because the conditions for the assembly of the Greek Army in the area between the Mesta and Struma rivers were more advantageous compared to those of the Bulgarians.


The forts were intended to accomplish their mission mainly through the use of their artillery. Therefore it was essential to maintain the effectiveness of their fire and the security of the personnel and the materiel for as long as possible. Since there was neither steel armour available, nor the capability to employ reinforced concrete in the construction of the forts, protection was achieved through the use of earthworks and shelters. The artillery was protected by in-depth coverage, which resulted in the increase in the size of the fort. Thus the fort at Rupel and the forts north of Kavala reached a perimeter of approximately 2 km. It was not possible to effectively guard such a large area with the only one infantry battalion, that had been allocated to each fort. Therefore the infantry occupied a simple line composed of trenches with no depth. The combat trenches were linked to each other by communication trenches. The shelters that were connected to the trenches provided protection from enemy artillery fire to the troops depending on the situation. Special attention was paid to the organization of the infantry and artillery observation posts, ammunition and food warehouses and dressing stations. Each fort was surrounded by continuous barbed wire.

During the Balkans war the Greek Army had acquired many machine guns from booty, which were distributed to the forts. The forts of Rupel and Kavala had more than 50 machine guns each. They were placed in the same trenches with the infantry. The result was that only a very few could cover effectively the terrain in front of the forts with enfilade fire.

The artillery offered only frontal coverage to the fort, while the sides and rear of the fort were left uncovered. Therefore, if the enemy managed to penetrate the fort on one side, it would constrict the fort from all sides. At any rate, the forts were intended to hold out for a few days, during which time the army would mobilize and assemble. The army then immediately would flank the forts.



SOURCE : HELLENIC ARMY GENERAL STAFF - ARMY HISTORY DIRECTORATE, A concise history of the participation of the Hellenic Army in the First World war 1914-1918, Athens 1999, pp. 32-36.




The Greek fortification in Eastern Macedonia

The Fortified Area of Kavala Fortress