Battle of Kosturino

The Battle of Kosturino was a battle between the forces of Bulgaria and Great Britain as part of the Serbian Campaign. the British were forced to retreat to Salonika.



Background
Following the intervention of Bulgaria in World War I, on October 1, 1915 the Austrian-German-Bulgarian offensive against Serbia started. The Serbian forces were forced to withdrawal after defeats in the Morava Offensive and Ovche Pole Offensive. Parts of the Franco-British force, that had landed in Salonika (Thessaloniki) in early October, was to advance to the North to support the retiring Serbian units in Kosovo.

French forces under the command of General Maurice Sarrail advanced deep into Serbian territory with the intent of reaching the Serbian Army at Niš. But on 19 October, they discovered that Bulgarian forces had already managed to cut the railway line to the north of Krivolak. Further French forces were sent into the area, but after the unsuccessful Battle of Krivolak between November 3 and November 23, and growing evidence that Serbian forces to the north had collapsed, the French Army was forced to retreat to Salonika.

The War Office in London had been more reluctant to sent troops into Serbia. Only on in the last week of October they had sent the 30th Brigade into Serbia, followed by the rest of the 10th (Irish) Division, which took over the French-held positions around Kosturino on November 21.

The Battle
The line held by the 10th Division, was in savage hill-top barren-rock country without vegetation. By the end of November, the weather conditions became worst. The exposed infantrymen suffered from cold rains and a raging blizzard. Furthermore, their health was already undermined by the unhealthy hot climate during the Gallipoli peninsula. By the end of November, already 1,656 men had been evacuated, many of them to be hospitalised with frostbite.

Very little fighting occurred until December 4, when it became clear that the Bulgarians had received reinforcements as their artillery fire became better directed and more concentrated. On December 6 and 7 they attacked and took Rocky Peak, taking 30 British prisoners. From here they had a good position to shell the British lines.

On December 8, the Bulgarian Army launched an all-out attack. General Mahon tried to coordinate his defensive operations with the retreating French Army to his left, but the enemy forces were too strong, about 4 times the size of the British. As newly arrived forces in Saloniki could not reach the front soon, because of bad roads, there was no alternative but to withdrawal. The Irish division withdrew in good order. Their casualties were about 1,500 men and eight guns.

By December 12, all allied forces had withdrawn into Greece. The Bulgarian Army was not allowed by the German High Command to enter Greek territory, as they still hoped that Greece would enter the war on their side.

Aftermath
With the Serbian forces cut off from outside help, they were forced to retreat westwards into Albania, where they were evacuated to the Greek island of Corfu by February 10, 1916. The Macedonian Front would stabilize between 1916 and 1918.