Battle of Florina begins

On 17 August 1916 the Bulgarian 1st Army of General Kliment Boyadzhiev went over to the attack on the western wing of the Salonika front. The columns set off during the night of 16/17 August, and according to Bulgarian studies, at about 4.30 p.m. soldiers of the 30th Sheynovo Infantry Regiment entered the Greek town of Florina, which the Bulgarians called Lerin. On the same day in Bucharest Romania signed with the Entente powers a treaty and a military convention, in which the Allies undertook to begin an offensive in Macedonia three days later. The Bulgarians forestalled them. The British official history of the operations in Macedonia, Bulgarian studies and Serbian accounts all give 17 August as the start of the attack; the Austrian official history gives 18 August.

A weak wing

General Maurice Sarrail, commander-in-chief of the Allied forces at Salonika, was preparing an attack whose main force was to be the reconstituted Serbian army. Its divisions were only just moving up to their assigned positions, and the long sector from Lake Ostrovo to Lake Prespa, with Florina and the railway from Salonika to Bitola, was very thinly held. According to Serbian studies it was defended by the Danube Division of the Serbian Third Army and a volunteer detachment of Lieutenant-Colonel Vojin Popović, known as Vojvoda Vuk, numbering about 1,500 men and without artillery. The Bulgarians knew that the Entente was preparing an offensive in connection with its talks with Romania, and for months had been demanding permission for an attack of their own. The order came on 14 August from the headquarters of the German army group of August von Mackensen.

The first day

The main blow was delivered by the reinforced Bulgarian 8th Tundzha Infantry Division of Major-General Todor Mitov. According to Bulgarian studies, its units drove the Serbs from the village of Gorno Kleštino and from several further positions before entering Florina in the afternoon. The Bulgarian 3rd Cavalry Brigade surprised a Serbian company in one of the villages on the road from Florina and almost completely destroyed it. The Serbian volunteers, attacked by an enemy many times stronger, had to withdraw and scattered into the mountains. The British official history put it briefly: the Bulgarian 1st Army advanced rapidly along the Bitola–Salonika railway, driving in the Serbian outposts. On the right wing a separate Bulgarian brigade descended between Lakes Ohrid and Prespa towards Korçë in Albania.

Further east, in the mountains above the Moglena (PL) basin, the Bulgarian 3rd Balkan Infantry Division was to pin down the Serbian Second Army. There the Bulgarians had no luck. Their 19th Regiment took several hills on the slopes of the Nidže range but had to give them up after a counter-attack by the Serbian Šumadija Division, losing, according to Bulgarian figures, 188 killed, 476 wounded and 39 missing. The British journalist Gordon Gordon-Smith, who accompanied the Serbian army, wrote that on the first day of the offensive the Bulgarians lost 400 killed and 600 wounded on this sector. From documents found on captured officers the Serbs learned that the aim of the 1st Army was to drive them from the mountains and occupy a line along Lake Ostrovo.

On both wings

The attack at Florina was part of a wider plan. At the eastern end of the front the Bulgarian Second Army was to enter Greek Eastern Macedonia, which Bulgaria had lost after the Second Balkan War, and advance to the Struma. Its attack from the area of Fort Rupel began during the night of 17/18 August. The Greek army, demobilised at the Entente’s demand, offered no resistance. For several more days Sarrail held to his original plan and sent the Serbian Vardar Division to the threatened sector at Florina. The next day the Serbs tried to retake the lost ground, but the battle was only just getting under way.