This is only a short description of events that preceded the outbreak of war. A more detailed version can be found in our links section.The events in Liége from 1914 July 28 until August 4, 08 AM are given in Liége, overture.
| 28 June | - Assassination of Archduke Franz Ferdinand of Austria in Sarajevo. |
| 23 July | - Austria sends an ultimatum to Serbia. |
| 27 July | - Belgium : All military personnel of the 1913 class, on temporary leave since 10 July 1914, are called back into service. |
| 28 July | - Austria-Hungary telegrams a declaration of war to Serbia. - Belgium : All military personnel on temporary leave are called into service. |
| 29 July | - Belgium : The 1910, 1911 en 1912 classes are called into service. |
| 31 July | - Austria-Hungary orders general mobilisation. - Germany brings army in state of alert (Kriegsgefahr zustand) a state of pre-mobilisation. - Russia orders general mobilisation. - 07 PM , Belgian government declares general mobilisation. |
| 1 August | - French Government orders general mobilisation. - British Government orders naval mobilisation. - German Government orders general mobilisation and declares war on Russia. - First day of Belgian mobilisation. - Hostilities commence on Polish frontier. |
| 2 August | - 06 AM, German army invades Luxembourg. - 07 PM, Germany sends ultimatum to Belgian government demanding passage through Belgium territory. - Hostilities commence on French - German frontier. - General von Moltke (Chief, German Great General Staff since 1906), appointed Chief of the General Staff of the German Field Armies. |
| 3 August | - 07 AM, Belgian Government refuses German demands - Belgian troops are ordered to open fire on every foreign military unit that crosses the border. - 19.45 PM, Germany declares war on France. - British Government orders general mobilisation. |
| 4 August | - 08 AM, German army crosses Belgian frontier. - British Government sends ultimatum to Germany. - Belgium severs diplomatic relations with Germany. - Germany declares war on Belgium. - Belgian high command order its troops that movements of the French army across the border are to be considered as friendly. - Two German airships pass over Brussels by night (first hostile act in the air). - Great Britain declares war on Germany at 11 pm. |
Source : WW1 document archive and Bibliography.