The Bulgarian fortifications against Turkey

The fortification of the borders with the Ottoman Empire started in 1885, after the proclamation of the Unification with the Eastern Rumelia and the concentration of the Bulgarian troops in the Southeast, against a possible attack of the Turkish Army. Being determinate to wage a defensive war, the Bulgarians fortified the positions of Kazal Agach, south of Yambol, Tarnovo-Seymen and Dupnitza with temporary field works. In addition they dug trenches and built some batteries in almost every pass which connected Bulgaria with Turkey, i.e. near Kyustendil, in the Rodopi, near Haskovo and near Burgas.

After the Serbo-Bulgarian War the relations with the Turks became friendlier, the attention of the army was turned towards Serbia and Romania, and the works of fortification were interrupted up to 1899, when they were resumed at Yambol, following a new worsening of the relations with Turkey.

From 1903 to 1912 the Bulgarian General Staff elaborated many different plans for the fortifications of the borders with Turkey, changing their design whenever the war plan changed.

The plan elaborated in 1903 was to arrange the following lines of defence:

A] Macedonian theatre of the operations :

- first line, with field fortifications : Garlyano, Novo selo, Chernata Skala and Slatino;

- second line, with field fortifications : Konövo, Malka and Goljama Fucha, and Dupnitza;

- third line, with temporary fortification : the great depot place (Lagerplatz) of Sofia.

B1] Thracian theatre of operations, in the Rodopi :

- first line, with field fortifications : Lazhene, Batak, Sotir, Byala Cherkva, Kuklen Topolovo e Sara Tash;

- second line, with field or temporary fortifications : Plovdiv, regarded as an important junction and barrage blocking the roads connecting the Macedonia and the Aegean Sea with the valley of the Maritza.

B2] Thracian theatre of operations, in Eastern Thrace :

the fortified area of Skobelevo – Tarnovo Seymen – Stara Zagora – Yambol, that should become a great place of arms, aimed at covering the concentration and the deploying of the Army in its strategic defensive position. It should be arranged in the following way :

- Skobelevo, should become a bridgehead on the left bank of the Maritza connecting Tarnovo with the river and covering the line of operation Stara Zagora – Chirpan;

- Tarnovo Seymen, placed in the main direction of the military operation, should become a great fortress opposed to Odrin, with temporary fortifications for a garrison of 30 000 men and 162 guns;

- Yambol should become another fortress, serving as redoubt of the whole defence in the south-eastern theatre of operations;

- Stara Zagora should become a stronghold to defend Sredna Gora and shelter the army, if it should be forced to withdraw from the Maritza valley.

In 1904, however, instead of starting the works, new reconnaissance were made in the places where the fortification should be erected, and in 1905 the adoption of a new war plan required a parallel change in the plan of the fortifications. They were moved back and arranged as follows :

A] Macedonian theater of the operations :

- first line : the heights of Konövo – Dupnitza;

- second line : the tre great depot place (Lagerplatz) of Sofia.

B] Thracian theater of the operations :

- first line : Haskovo – Tarnovo Seymen – Yavuz dere – Sinapli – Hassar Begli – Chukurly – Kazal Agach;

- second line : the Sredna Gora, from Stara Zagora to Binkos;

- third line : the passes of the Stara Planina;

- fourth line : last reduit – Pleven or Veliko Tarnovo.

In this new plan Tarnovo Seymen increased its importance and instead of a simple bridgehead at Skobelevo, a series of fortified positions were planned on both the banks of the Maritza. On the right bank three bridgeheads should be erected at Semizche (Klokotnitza), Kurudzhitza and Ovadzhik along a front of about 25 km southwards. On the right bank, parallel with the Sazla dere three more strongpoint should be erected at Teke, Kumköi e Kara Bunar. Some bridges should be built in order to link the two banks of the Maritza.

Even if the plan for most of the fortifications had been processed, once again the works never started. The adoption of a new war plan in 1908 did not require any change in the fortification of the borders. Even if this time the General Staff adopted an offensive strategy, the old succession of defensive lines was retained both in Macedonia and in Thrace.

Finally with the war plan adopted in 1910-11 the defensive line was again moved back, and a new arrangement was planned. The fortifications were grouped in four fortified positions :

- Macedonian theatre of the operations : Dupnitza and Sofia;

- Thracian theatre of the operations : Tarnovo Seymen and Yambol;

- Black Sea coastline : Varna and Burgas;

- the rear : Shumen and Vidin.

In September 1912, at the declaration of war against Turkey, the situation of the Bulgarian fortifications of the borders with the Ottoman Empire was far from satisfactory. All the positions chosen by the General Staff over the years were unfinished or outdated and constituted a great obstacle against a Turkish offensive.

On the Dupnitza position three strongpoints had been planned : at Konövo, for 30 000 rifles and 120 guns; at Kadin most, for 15 000-20 000 men 60 guns; and at Dupnitza, for 24 000 men and 50-60 guns. The work was carried out actively untill 1906 and more even before, but they were never finished.

In the Rodopi the General Staff had planned 17 barrages to block the mountain passes and two strongpoints in the rear at Panagyurishte and Chukurly, but at the beginning of the war, in 1912, they were not finished. As for Plovdiv, again, a plan had been elaborated, but the works of fortification never started. Only 3 small earthworks had been built on the west of the gorge debouching at Kuklena and near that village.

The Tarnovo Seymen position should be composed by 10 fortified groups, 6 on the first line of defence (4 on the right and 2 on the left bank of the Maritza), and 4 on the second line (all on the left bank), but at the outbreak of the war against Turkey only the first line was finished. In 1903 had been built 9 redoubts on the right bank of the Maritza, along the line Maritza – Tarnovo – Malak Jurendzhek – Maritza, and 3 bridges linking the two bank of the river. Afterwards the works were interrupted, and resumed only in 1912. Untill the outbreak of war, another bridge and 9 strongholds were built : 4 were along the line planned in 1903, on the right bank of the Maritza, while the remaining 5 were on left bank, along the line Dyudyukcheni (Svikovo) – Smavli (Troyan).

The fortification of Yambol position started in 1899 with the construction of 4 redoubts located 2000 to 2500 metres out from the city centre. Then the works were interrupted. In 1910 a new plan was elaborated to change it into a great fortress for 23 000 rifles and 60 guns. The defensive line was moved forward and 24 strongholds were planned, but they were finished only after the outbreak of the war. At Kizil Agach, on the road that connected Yambol with Odrin, a redoubt, some infantry breastworks and a six-guns battery were built to cover the plain of the Tundzha

Even Stara Zagora should be changed into a great fortress with 43 strongholds. The earthworks were nearly finished in 1905, but afterwards the works were interrupted and never resumed.