| 28 June | Archduke Franz Ferdinand of Austria is assassinated in Sarajevo by Gavrilo Princip from Serbia. |
| 28 July | Austria-Hungary declares war on Serbia. |
| 1 August | Germany declares war on Russia. |
| 4 August | Germany marches its army through Belgium to attack France. Britain goes to Belgium’s aid and declares war on Germany. |
| Early August | Polytechnic members are asked to enlist and The Rangers company is mobilised. |
| 6 August | Ambulance training classes begin at the Polytechnic. |
| 7 August | First members of the British Expeditionary Force land in France. |
| 13 August | First squadrons of the Royal Flying Corps arrive in France. |
| September | Polytechnic establishes its War Fund to help men fighting in Europe. |
| 2 September | Lt-Col Ian Hogg, son of Quintin Hogg, dies fighting in Northern France. |
1915
| 19 January | First Zeppelin air raid on Britain kills 7 people. |
| 14–15 February | Captain Lionel Studd, son of JEK Studd and Major Vincent Hoare, son-in-law of Quintin Hogg are killed fighting near Ypres, Belgium. |
| March | British Government asks women to sign up for war work. |
| Over 1,600 Polytechnic men are on active service. | |
| 22 April | Chemical warfare begins with the first use of gas in the trenches. |
| 23 May | Italy declares war on Germany and Austria. |
1916
| 25 January | British Government passes the Military Service Act – Conscription is introduced in Britain. |
| 21 February | Battle of Verdun begins – the longest and costliest battle of the war. |
| 1 July | Battle of the Somme begins – the British outnumber the Germans but 7 British die to every 1 German. The total number of British casualties on the first day is 60,000. |
| 18 November | Battle of the Somme ends with a total of over 1 million casualties sustained during the battle. |
| 20 December | Battle of Verdun ends with a total of over 700,000 casualties sustained during the battle. |
1917
| Training courses begin at the Poly for the rehabilitation of soldiers. | |
| 6 April | America declares war on Germany. |
| 6 December | German bombers attack London killing 162 people. |
1918
| 1 April | The RAF is formed. |
| July | At the Battle of the Marne the Allies start driving the Germans back. |
| 9 November | Kaiser Wilhelm II abdicates and flees Germany. |
| 11 November | Armistice Day – peace is agreed. The Poly holds a service of thanksgiving |
1919
| January | Approximately 1,000 men and women have now been trained at the Polytechnic. |
| 28 June | Treaty of Versailles is signed. |
| July | Memorial service held at the Poly for fallen members of The Rangers. |