A look at the major events of the conflict during October 1915.
Saturday 2nd – The Greek Premier (Eleftherios Venizelos) asks the British and French to land troops at Salonika as soon as possible.
Sunday 3rd – Germans recapture part of Hohenzollern Redoubt on the Western Front (which had been taken by the Allies in the Battle of Loos).
Monday 4th – The Entente Powers send an ultimatum to Bulgaria.
Tuesday 5th – Russia (being of impatient bent) informs Bulgaria that diplomatic relations are at an end. In Greece the political crisis continues to grow as King Constantine refuses to support the policy of his Premier. Venizelos then resigns.
Wednesday 6th – Serbia is invaded by Germany, Austria-Hungary and Bulgaria (proving Russia right in this instance). King Constantine of Greece assures Britain that his country will remain neutral (whilst mobilising his forces nonetheless).
Thursday 7th – Austro-Hungarian and German forces attack across the Danube into Serbia.
Friday 8th – The new Greek Government (lead by Alexandros Thrasivoulou Zaimis) confirm their policy of neutrality.
Saturday 9th – Belgrade is captured by Austrian forces. Wumbiagas, in the Cameroons, is captured by British forces.
Sunday 10th – The Greek Government, keeping to their stated neutrality, reject Serbia’s plea for help again invasion.
Monday 11th – Bulgarian forces begin full hostilities against Serbia.
Tuesday 12th – Following a court-martial, British nurse Edith Cavell is executed by German firing squad for helping POWs escape from Belgium to Holland (over 200 men evaded capture thanks to her work between November 1914 and July 1915).
Wednesday 13th – A sustained Zeppelin airship raid on London and the Eastern counties results in over 200 casualties. French Foreign Minister Theophile Delcasse resigns and is temporarily succeeded by Rene Viviani.
Thursday 14th – Bulgaria officially joins the Central Powers, declares war on Serbia and invades Macedonia.
Friday 15th – Great Britain and Montenegro declare a state of war with Bulgaria. The Romanian Government refuse assistance for Serbia.
Saturday 16th – France declare war on Bulgaria and Allied forces begin a naval blockade of Bulgaria’s Aegean coast.
Sunday 17th – The British Government offer Cyprus to Greece in return for supporting Serbia against Bulgaria.
Monday 18th – The Third Battle of the Isonzo begins between Italian and Austrian-Hungarian forces along the Soca River in western Slovenia.
Tuesday 19th – Italy and Russia declare war on Bulgaria.
Wednesday 20th – The Greek government reject Britain’s offer of Cyprus.
Thursday 21st – Allied naval squadrons bombard Dedeagatch in Bulgaria. Bulgarian forces capture the city of Veles in Serbia.
Friday 22nd – Bulgarian forces capture the cities of Kumanovo and Uskub on the Southern front.
Saturday 23rd – The German armoured cruiser Prinz Adalbert is sunk by British submarine E8 in the Baltic.
Sunday 24th – La Courtine in Champagne is captured by French forces. Venice is bombed by Austrian aircraft.
Wednesday 27th – William Morris Hughes replaces Andrew Fisher as Prime Minister of Australia.
Thursday 28th – British battle cruiser HMS Argyll runs aground and is wrecked on Bell Rock of the east coast of Scotland. General Sir Charles Munro takes command of the Mediterranean Expeditionary Force.
Friday 29th – French Premier Rene Viviane and Minster for War Alexandre Millerand both resign.
Saturday 30th – Aristide Briand succeeds Viviani as Prime Minister of France.
I apologise for a lack of pictures to illustrate the above but I was unable to find ones that I could legitimately source.