The Vardar in the First World War

The Vardar, Axios in Greek, flows from the mountains of western Macedonia through Skopje and Veles into Greece and enters the Thermaic Gulf west of Salonika. The only railway line from Salonika northwards, to Serbia, ran along its valley, and that made the valley the axis of the whole Salonika front. In 1915 the French went up it to help the Serbs and had to turn back, for the next three years the front crossed it on the Greek–Serbian border, and in September 1918 the offensive that took Bulgaria out of the war was named after the river.

The Vardar corridor

The river is 388 kilometres long, 76 of them in Greece. The British official historian Cyril Falls wrote that it is the Vardar corridor which gives Salonika its strategic significance. The mountains around Macedonia are almost impassable, and through the valley ran the route from Niš to the Aegean, along which the Niš–Salonika railway had been laid. Even so, when the war came, the valley itself had only bridle paths and primitive cart tracks, and in the Serbian part, up to Veles, the only bridges across the river were the steel railway bridges.

After the Second Balkan War the Treaty of Bucharest divided the valley: Serbia received the upper and middle reaches, Greece the mouth with Salonika. Bulgaria, which also wanted Macedonia, did not accept this. When it joined the Central Powers in 1915, its reward was to be Macedonia with the Vardar corridor. Falls called it “a bargain in valleys”.

1915: help that never arrived

In October 1915 the Bulgarians attacked Serbia from the east and quickly reached the river. Around 20 October their cavalry took Veles, and on 22 October they entered Skopje. The railway from Salonika was cut, and the Serbs were cut off from their allies, who had only just landed at Salonika. General Maurice Sarrail’s French moved up the valley by rail and on 21 October fought their first action against the Bulgarians near Strumica station.

For more than five weeks two French divisions held bridgeheads on the Vardar and the Crna near Krivolak, but they never reached the Serbs. At the beginning of December the retreat down the river began. The French rearguard covered the Vardar gorge at Demir Kapija, and the Bulgarians drove the British off the Kosturino ridge. On 12 December the Allies crossed to the Greek side of the border, and on 15 December they moved away from it towards Salonika. The Bulgarians stopped at the border.

A front across the valley (1916–1917)

For almost three years the front crossed the Vardar valley on the old Greek–Serbian border. East of the river, as far as Lake Dojran, the Bulgarians held a tangle of hills that Falls called a barrier of immense strength. West of it the border ran along high mountain ridges. The valley itself remained one of the few routes along which an attack was possible. In May 1916 the wreck of the airship LZ 85, shot down over Salonika, fell into the marshes at the river’s mouth.

In 1917 the Allies twice tried to get moving. In April and May the British attacked at Dojran and were repulsed. Sarrail’s May offensive, recorded in the British chronology as the Battle of the Vardar, was fought mainly some tens of kilometres further west, and on the river itself the French and Greeks only pushed their outposts forward. A year later, on 30 May 1918, the Greeks took the Skra di Legen salient, a dozen or so kilometres west of the Vardar.

The breakthrough (1918)

General Louis Franchet d’Espérey based his plan on the valley. Gradsko and Krivolak on the Vardar, about 55 kilometres behind the front, were the most sensitive point of the whole Bulgarian defence: the railway from Salonika, the narrow-gauge line from Bitola and the roads linking the two wings all met there. Instead of going for them directly, through the hills at Dojran, on 15 September the Serbs and French broke through the front in the mountains at Dobro Pole.

Before dawn on 21 September the Serbs saw from the mountains the glow of burning villages and depots in the Vardar valley, and in the evening the heads of their columns reached the river. That same night the Bulgarian First Army abandoned its positions at Dojran and the British set off in pursuit. On 23 September the Serbs forced the Vardar, and on 24 September the French and Serbs took Gradsko, where they captured 19 guns and about 40 locomotives. The Bulgarian front had been cut in two.

From there the advance went up the river. On 26 September the Serbian First Army took Veles, and at dawn on 29 September French cavalry burst into Skopje and cut off the retreat of the German and Bulgarian troops further west. That evening Bulgaria signed the armistice at Salonika. The Vardar offensive was the first breach in the bloc of the Central Powers.