Tough battles between the Bulgarian and British armies were fought in other parts of the Front, particularly in the Lake Doiran area. The first military confrontations took place in October 1915 with the entry of Bulgaria into the war. For instance, small troops of the Bulgarian army tried to cross the Vardar River through Valandovo and Udovo and thus cut off the rail and road links between Thessaloniki and Skopje.
In early December of the same year, and after the withdrawal of the French and British armies from Thessaloniki, a front was established in the Lake Doiran area, which brought Lake Doiran closer to the military positions of the two armies. During the next three years, until September 1918, several significant battles were fought in the area, resulting in a large number of casualties and the almost complete destruction of the town of Doiran. The first major battle took place in August 1916, the Allied offensive at Doiran was part of a series of activities along the Front Line. The offensive began with a strong artillery preparation, followed by the infantry shot, a method very characteristic of this war. All offensives were repulsed by the well-established Bulgarian army.
The next attempt of offensive action by the Allies took place in 1917. Fights had already been fought in February, but more serious Allied offensives took place in April and May, and then in October. Towards the end of April, the British army began an offensive to try to cross the Bulgarian lines. Offensives continued in May, but all were repulsed by the Bulgarian army. The losses of the British army were significant. In October, after three days, the offensive was halted due to the strong resistance of the Bulgarian armies. After the interruption of the offensive, the line of this part of the front line stabilized.
No significant offensive was observed until September 1918, before the third Battle of Doiran took place. This third attempt by the Allies was also unsuccessful. However, following the breakthrough of the Dobro Pole Front, faced with the risk of being divided and surrounded, Bulgarian troops withdrew. The consequences for Doiran and its surroundings have been devastating. Almost the entire population was forced to relocate, and the proximity of the post-war border led to isolation and economic decline. Damage to St. Ilija's Church to Star Doiran, the trenches, memorial stelae of the Bulgarian and British armies near Kalatepe near Doiran, as well as the British cemeteries at Polikastro and the Greek military cemeteries at Valandovo testify to the battles of Doiran.