Dedeagatch agreement

On 22 September 1915 the Bulgarian government announced the terms of its agreement with Turkey on a change of the border in Thrace. The British chronology of the war calls it the “Dedeagatch agreement” and records its conclusion under this date. The name came from the Aegean port of Dedeagatch (PL), today the Greek Alexandroupoli. A safe route to it was the most valuable gain from the agreement for Bulgaria. The announcement coincided with the decision to mobilise: late in the evening of the same day the tsar signed the decree of general mobilisation of the army.

A border along the Maritsa

The agreement itself had been signed in Sofia on 6 September, in secret, together with the treaty of alliance with Germany. According to the published terms, the new border ran along the valley of the Tundzha right up to the outskirts of Edirne, with the railway station at Karaağaç on the Bulgarian side, and further south along the Maritsa, about two kilometres from its left bank. The whole railway line from the interior of the country through Didymoteicho (PL) to Dedeagatch thus found itself on Bulgarian territory. Until then trains travelling to the Aegean had passed through Turkish land.

Sources give different dates for the final signature. The British Ministry of Information chronology of 1918 records that the text of the convention was sent to Constantinople on 15 September and signed on 25 September. The American envoy in Sofia, Lewis Einstein, wrote in a November report to Washington that the protocol was signed immediately after news of the mobilisation decree arrived. According to his informants, the Turkish delegates waited at the railway station in Didymoteicho and signed only when the telegraph confirmed that the decree had been proclaimed. Einstein stressed that the Turkish concessions depended entirely on Bulgaria entering the war.

Preparations for handing over the land

Turkey began preparing to give up the land. The handover was to begin on 11 October, but the border on the ground still had to be marked out by a commission with a German, an Austrian and a Swede, meeting at Karaağaç. The inhabitants of the ceded lands, mostly Muslims, were seized with anxiety. The Ottoman authorities ordered carts to be gathered around Didymoteicho to prevent a mass flight of the population. The Minister of War, İsmail Enver, fearing that indignation at home would undermine the agreement, insisted that Karaağaç be evacuated as quickly as possible.

Dedeagatch was Bulgaria’s only port on the Aegean, won in the Balkan Wars, but exposed to the Entente fleet from the start. As early as the beginning of October the British announced that they would stop all goods bound for Bulgaria through this port. According to Einstein, the handover of the land itself took place on the day Bulgaria opened hostilities against Serbia.