The Salonika Campaign was part of the First World War and took place in the Balkans between 1915 and 1918. It is also known as the Macedonian Front.
The campaign began in October 1915, when Allied forces landed at the port city of Salonika, in northern Greece. These forces were mainly made up of soldiers from Britain and France.
Their main goal was to help Serbia, which was being attacked by several enemy countries.
Serbia had already been fighting since 1914 and was exhausted by the time Bulgaria attacked it in 1915.
The Allies hoped that by sending troops to Salonika they could support Serbia and stop the enemy advance in the Balkans.
However, poor planning, difficult transport, and slow decision-making meant that the Allied forces arrived too late to make a difference.
By the time the Allies were ready to move north from Salonika, Serbia had already been defeated and occupied.
The Serbian army was forced to retreat through harsh mountain terrain during the winter, suffering heavy losses.
This failure raised questions about whether the Allies should withdraw their troops from Greece altogether or remain in the region despite the setback.
The Serbian had to retreat from the Bulgarians in November 1915
In early December 1915 British and French troops fought Bulgarian soldiers in the Battle of Kosturino.
The Bulgarians won the battle, which forced the Allied armies to leave Serbia and move south into Greece.
During the fighting, the British 10th (Irish) Division fought hard to hold their position.
The soldiers faced strong attacks, very cold weather, and rough land.
After suffering many losses, they were eventually ordered to retreat into Greece.
Infantry manning part of the 10th (Irish) Division's line on the Kosturino Ridge, December 1915.
After the defeat at the Battle of Kosturino in December 1915, the British forces faced a big problem. They had tried to help Serbia fight against the Central Powers but had been pushed back. This loss meant they could not keep their positions in the Balkans safely.
The British had to decide whether to keep trying to fight there or retreat to save their soldiers.
It was a tough choice because staying could mean more losses, but leaving felt like giving up on their allies.