4 August: Outbreak of WWI. A state of war is declared at 11pm after Austria-Hungary rejects an ultimatum by Great Britain to desist from hostilities.
25 - 26 August: Battle of Le Cateau. This rear-guard action following the retreat of British and French troops after the Battle of Mons involves many Scottish regiments. It delays the advance of the Germans but results in over 7,000 British casualties.
12 September: Appeal for First Scottish Women’s Hospital. Campaign launched by physician and suffragist Elsie Inglis to raise funds for the first Scottish Women’s Hospital for the Foreign Service Committee with the aim of providing all female-staffed relief hospitals for the Allied war effort.
25 April: Gallipoli. The 52nd Lowland Division, including a number of Scottish Battalions, are involved in the later stage of this ill-fated Allied operation to secure the strait of the Dardanelles and capture Istanbul to gain entry to the Black Sea. The British have 205,000 casualties including 43,000 fatalities.
9 May: Battle of Aubers Ridge. Scottish regiments sustain heavy casualties during this Franco-British offensive. An estimated 2,000 out of 11,000 British casualties are Scottish.
22 May: Train crash at Quintinshill. A troop train transporting mostly Territorial soldiers from the Leith-based 7th Battalion of the Royal Scots regiment headed for Gallipoli collides with a local passenger train killing 214 officers and men. A further 246 people, mainly soldiers, are injured.
July: Munitions of War Act. Women are allowed to assume jobs in munitions factories, such as those in Glasgow and Gretna, previously restricted to men.
25 September: Battle of Loos. Over 30,000 Scottish soldiers serve in the largest British offensive mounted on the Western Front in 1915. Half of all casualties are Scottish with five awarded Victorian Crosses.
8 December: Edinburgh-born Douglas Haig promoted to Commander-in-Chief of the British Expeditionary Force.
January: Military Service Act passed. Conscription introduced (compulsory military service) up to the age of 50.
April: Munitions production begins at H.M. Factory, Gretna. It becomes the UK’s largest cordite factory.
2 April: Edinburgh bombed by two German Zeppelins in first-ever air raid on Scotland. The first reports of bombs landing in the Leith area of Edinburgh arrive shortly before midnight. Over the next 35 minutes, 24 bombs are dropped on the capital killing 13 and injuring 24.
31 May: Battle of Jutland. The largest and only naval battle fought between the Royal Navy’s Grand Fleet (including the Royal Australian and Royal Canadian navies) and the Imperial German Navy’s High Seas Fleet during the war. While Britain and its allies sustain far greater casualties, Germany never again successfully challenges British control of the North Sea.
5 June: Sinking of the HMS Hampshire. After setting sail from Scapa Flow to transport the British Field Marshall Earl Kitchener on a diplomatic mission to Russia, the armoured cruiser is struck by a mine laid by a German U-boat and sunk off the west of the Orkney Isles. 643 of the 655-strong crew, including Kitchener, are drowned.
1 July - 13 November: Battle of the Somme. Three Scottish divisions – 9th, 15th (Scottish), 51st (Highland) – and numerous Scottish battalions in other units participate in one of the bloodiest battles of the conflict. British casualties exceed an estimated 350,000.
9 April: Battle of Arras. 44 Scottish battalions and 7 Scottish-named Canadian battalions make up the largest concentration of Scots to have fought together during the war. A third of the 159,000 casualties are Scottish.
5 February: Sinking of the SS Tuscania. A luxury liner carrying more than 2,000 American troops to France is torpedoed by a German U-boat off the coast of the Isle of Islay. An estimated 230 lives are lost.
6 October: Sinking of the HMS Otranto. Just eight months later, a Royal Navy armed merchant cruiser sailing from New York to Glasgow collides with the steamship HMS Kashmir in a storm and sinks near Machir Bay off the west coast of Islay. More than 400 lives are lost.
11 November: Armistice Day. Armistice between the Allies and Germany signed at 11am marking the official end of the war.
1 January: Loss of HMS Iolaire. The Iolaire is sailing soldiers to the Isle of Lewis when it strikes rocks and sinks off the coast of Stornoway. 205 men out of a crew of 284 are drowned.
21 June: The Scuttling of the German Fleet at Scapa Flow. 72 warships of the German High Seas Fleet deliberately sink themselves following the order of Rear Admiral Ludwig von Reuter after being interned at Scapa Flow as a condition of the Armistice agreement.
January 1918 - December 1919: Spanish Flu Pandemic. Glasgow becomes the first city in the UK to be affected by this deadly influenza pandemic which claims the lives of millions worldwide.