the other from the south towards Skopje. The Bulgarian Army rapidly broke through the weaker Serbian forces which tried to block its advance. With the Bulgarian breakthrough, the Serbian position became hopeless; their main army in the north faced either encirclement and enforced surrender, or retreat. Marshal Putnik ordered a full Serbian retreat, southwards and westwards through Montenegro and into Albania. The Serbs faced great difficulties: terrible weather, poor roads and the need for the army to help the tens of thousands of civilians who retreated with them. Only soldiers reached the Adriatic coast and embarked on Italian transport ships that carried the army to Corfu and other Greek islands before it traveled on to Thessaloniki. Marshal Putnik had to be carried during the whole retreat; he died just over a year later in a French hospital. The French and British divisions marched north from Thessaloniki in October 1915 under the joint command of French General Maurice Sarrail, and British General Bryan Mahon. On 20 October, the French divisions reached Krivolak on the Vardar river, while the British occupied the strategically important area between the Kosturino Pass, Vardar and lake Doiran. This advance aided the retreating Serbian Army, as the Bulgarians had to concentrate larger forces on their southern flank to deal with a possible invasion into their territory. The French command then became aware of the Bulgarian presence in the Babuna Pass between Veles and Bitola, and attempted to reach a group of Serbian soldiers located to north west of the pass. This led to the Battle of Krivolak which lasted between 5 and 19 November 1915. The French slowed down the Bulgarian advance, thus enabling the bulk of the Serbians to escape; however, Bulgaria retained the dominant mount Arkhangel west of Gradsko, forcing Sarrail to initiate a retreat towards Thessaloniki. The British forces had in the meantime only encountered small bands of Bulgarian deserters, who informed them that the Second Bulgarian Army under General Georgi Todorov had been reinforced at Strumica. On 26 November 1915, a combination of high wind, rain and snow rendered the already steep terrain impassable. The downpour continued until 3 December, soaking the soldiers to the skin and destroying their greatcoats. A total of 23 officers and 1,663 soldiers had to be evacuated back to Salonika due to frostbite and exhaustion, depleting the 10th Irish Division. The division's efficiency was further lowered by the