The crushing of Serbia

Hemmed in from north, west and east, the
red and orange  arrows show the only 
direction the battered Serbian armies could take

Despite Grey’s immense diplomatic efforts to persuade Bulgaria to stay neutral, the scale of the Russian defeats on the Eastern Front increased the pressure on the Allies to achieve something out of the mess of Gallipoli. Bulgaria (correctly) saw Suvla Bay as a decisive failure by Britain, but Serbia still refused to concede any hard won Macedonian territory to Bulgarian demands – a suicidal stance. Grey also tried (unsuccessfully) with guarantees and the offer of 200,000 troops, to induce Roumania and Greece to enter the war. Once Bulgaria had committed, effectively providing an eastern pincer for the German drive into Serbia from the north, the Serbian army was doomed. In Churchill's words "On October 9th the storm of ruin burst upon the Balkans".
The desperate attempts by the allies to support and supply them from Salonika was something of a sideshow that brought no relief to the hopeless Serbian position.

Serbia’s strategic position was parlous. Effectively she was trapped in a dep salient, with German forces poised to the north; Austria controlled Bosnia to the west; and Bulgarian forces to the east. In the near inevitable event of Serbian forces being overwhelmed, the only course of retreat was south west towards unfriendly Albania, and even more unfriendly mountain ranges. Their only hope was that allied forces advancing from Salonika might turn the Bulgarian flank and stop their advance.

Mackensen’s objectives were straightforward. Unlike the Bulgarians he was more interested in securing communication lines to Constantinople than annihilating the Serbian army (already worn down by two previous major campaigns). He wanted control of the Danube waterway, and the Ottoman railway running from Belgrade eastwards. The river was easier to secure than the railway, and a huge German logistical operation went on behind the front line to enable weapons and reinforcements to be transported rapidly to Turkey for the next stages (much of the weaponry was bound for Gallipoli). To capture and control the railway line required a deeper invasion of Serbia, and control of difficult mountainous territory. It was in this regard that Bulgaria’s entry from the east produced a fatal situation for Serbia.

Bulgarian forces marshalled in 1915

On 12^th October, the Bulgarians attacked with two strong columns, and rapidly drove the Serbian defenders westwards for more than 100 miles. Communications with Salonika were cut off by this move, sealing the fate of the diminished Serbian army. On the 20^th, the Bulgarians reached the city of Uskub (now Skopje), the key junction of all overland routes in southern Serbia.  By 26^th, Bulgarian and Austrian forces had linked with each other, and all of northern Serbia had been taken. At this stage, the remnants of the defending army were in two separated groups, totalling around 150,000 men, and were forced to fight a series of rear-guard actions and retreats to head towards the hostile Babuba pass - already deep in snow - and a retreat into Albania. They acquired many refugees on that desperate journey, and deaths from exposure, starvation and disease were numerous.

Part of the Serbian long retreat 1915

Only two pieces of good fortune attended this catastrophe. Firstly, the Germans did not join the Bulgarians in pursuit of the Serbs – they were more concerned with pressing on to Turkey. Secondly, the leader of Albania, Essad Pasha, somewhat unexpectedly, declared war in favour of the allies, and supported the eventual escape of around 130,000 Serbian troops. Remarkably, nearly all of these re-entered the conflict via Salonika. Most of the refugees were evacuated to southern Italy.

Meanwhile the Allies, unable to provide any meaningful support to the Serbs, were at least establishing a formidable beach-head at Salonika, and this would prove to be a significant development. One remarkable French excursion into Serbia, led by Sarrail (who, as we have seen, had a point to prove against Joffre) is worthy of a separate blog episode, but made no impact on the destruction of Serbia.

Final words on this from Churchill “During all this misery and destruction large Anglo-French forces assembled at Salonika… as helpless spectators, and the Allied army on the Gallipoli peninsula was left to rot”.