[1] Sarrail's openly socialist political connections made him a rarity amongst the Catholics, conservatives and monarchists who dominated the French Army officer corps under the Third Republic before the war, and were the main reason why he was appointed to command at Salonika.

Sarrail ended up commanding a multinational Allied force amidst political intrigue and a state of near civil war in Greece, whose King Constantine was pro-German, whilst the Prime Minister Venizelos was pro-Allied and also keen to gain territory from the Turks in western Anatolia.

In 1911 he was promoted General de Division when his radical Socialist friend Caillaux formed his first government, and on 1 November 1913 he was given command of VIII Corps.

However, during the Battle of the Marne, unlike those other French generals, Sarrail was ordered simply to pin down German Crown Prince Wilhelm's Fifth Army opposite him, in the vicinity of Verdun.

Joffre criticised Sarrail's men for abandoning equipment and officers for poor leadership and demanded that he "re-establish order, taking whatever measures necessary".

At 20.00 on 8 September Joffre authorised Sarrail to break contact with the Fortified Region of Verdun, so as to shift his forces west and better block the German advance.

After attacks by French artillery, directed by aircraft, had failed to do the trick, Sarrail spent much of the winter of 1914–15 attempting to drive the Germans from the Heights.

Dubail sent two separate reports to Joffre: the one on operations was partly positive, but criticised Sarrail's plans for being "too simplistic" and for keeping his divisions in "rigid zones".

During the preparations for the upcoming offensive, Castelnau supervised Humbert closely, criticising Sarrail's legacy of poor construction of obstacles and shelters and "defective practices" amongst the artillery.

[6][23] Viviani (French Prime Minister) shored up his coalition government by appointing Sarrail, a republican socialist general, to command an expedition to the Eastern Mediterranean.

After meeting Millerand (War Secretary) on 3 August he accepted on condition the name of his force was changed to "Army of the Orient", a title with Napoleonic overtones, and that it was reinforced with an extra four divisions, and was not under British generals.

Throughout August President Poincaré, Viviani and Millerand pushed Joffre to release four divisions for the planned Asian expedition, and he eventually promised to do so after his autumn offensive.

Sarrail, asked by the War Minister for his views, recommended that the British be urged to maintain their presence at Gallipoli for reasons of Allied prestige.

Under Serb pressure he agreed to advance as far as Krivolak, but not Skopje (capital of Macedonia, which was part of Serbia at the time), but was checked in the Vardar and Tcherna Valleys.

Castelnau reported to Joffre, Briand, Gallieni and Poincare on Christmas Day, criticising Sarrail for the same issues which had led to his relief from Third Army, and for his "grave mistakes" in remaining at Salonika and only visiting the front at Krivolak once.

On 4 March 1916, two days after the Germans attacked Verdun, Joffre – to the irritation of Robertson – ordered Sarrail to "study" an offensive to pin down Central Powers troops.

The refitted Serb divisions were transported into Salonika, escorted by a French naval squadron which had based itself at Argostoli, again to the fury of the Greek government.

Under Allied political pressure King Constantine dismissed Prime Minister Skouloudis on 22 June, but refused to disarm the Greek troops at Salonika.

[42] Lieutenant General Sir George Milne (in a letter to Robertson, dated 20 July), who succeeded Mahon in command of British forces in Salonika, thought Sarrail "A strong man with big ideas and outlook with great brain power but of a conceited, excitable, impetuous and unscrupulous nature … Possibly a good strategist but not a great tactician … His mental calibre far and away above his Staff".

Two French divisions and a Russian brigade attacked towards Kenail and the British up from the Struma Valley, at each point meeting trenches dug under German supervision.

[34][49][54] On 1 December 3,000 French soldiers and British marines were landed in Athens, seeking to recover ten batteries of mountain artillery, but they were withdrawn under cover of naval gunfire after they had suffered 212 casualties, including 54 deaths, at the hands of Greek troops and hostile crowds.

To Prime Minister Briand's and Joffre's surprise, Rocques returned recommending that Sarrail's forces be built up to thirty divisions ready for an attack on Bulgaria.

Coming on the back of the disappointing results of the Somme campaign and the fall of Romania, Rocques' report further discredited Briand and Joffre and added to the Parliamentary Deputies' demands for a closed session.

Nevertheless, Romania also partially contributed to the failure by not dispatching 150,000 troops towards Bulgaria, in conjunction with Sarrail's offensive, as agreed upon in a military convention on 23 July in Chantilly.

Lloyd George, now British Prime Minister and keen to avoid a repetition of the Battle of the Somme, thought him "a remarkable, fascinating character, handsome, impulsive, full of fire", although fearful about the effect on US opinion he rejected Sarrail's suggestion that he be given a fortnight to crush the royalists in Athens.

[61][62] By the time of St-Jean-de-Maurienne (Anglo-Franco-Italian talks on 19–20 April) Sarrail had still not launched the offensive promised three months earlier, and Lloyd George had lost patience with him and come reluctantly to agree with Robertson that the British contingent at Salonika might be better employed in Palestine.

Another British attack in the Struma Valley was more successful, although in the centre of the line the French offensive under Grossetti, launched from Monastir on 9 May, failed amidst disease and logistical failures (severe penalties were inflicted on those caught scrounging food).

[64][65] Morale suffered badly and friction broke out amidst the different Allied nationalities, with troops having had no home leave in a year, or nearly two in the case of men who had been at the Dardanelles.

In September 1917 he ordered a small force to take Pogradec, and recognised the former Turkish general Essad Bey Pasha, seen as little more than a bandit, as "President of the Provisional Albanian Government".

[65][66] With France narrowly surviving political and military crisis in 1917, Sarrail's association with the socialist politicians Caillaux and Malvy, now suspected of treasonable contacts with the Germans, sealed his fate.