The outbreak of World War I was the result of many political and military developments in Europe in the beginning of the twentieth century. The early invasions established two clear fronts – the Western Front and the Eastern Front – on which war would be fought.
Austro-Hungarian Invasion of Serbia
Following the assassination of Archduke Franz Ferdinand in June 1914, Austria-Hungary served Serbia a harsh ultimatum. Although Serbia had agreed to most of the terms, Austria-Hungary turned aggressive following a failure to comply with all the terms. War was declared on July 28, 1914, and Austria-Hungary bombed Belgrade, Serbia.
German Invasion of Luxembourg
With the outbreak of war, Russia started mobilization of troops. Threatened by this, Germany asked Russia to halt mobilization of troops on July 31, 1914. With no promise of neutrality coming forth from France, Germany set out to implement the Schlieffen Plan. Desiring to fight and overcome France quickly before facing the Russian Army, Germany invaded Luxembourg on August 2, 1914.
German Invasion of Belgium
With the invasion of Luxembourg, Germany demanded that traditionally neutral Belgium allow German troops to march through and thereby assist in its invasion of France. King Albert of Belgium decided to resist German invasion. On the night of August 3, 1914, German troops invaded Belgium. Belgium’s stiff resistance was partly the cause of the delay of the Schlieffen Plan and brought Britain into the war.
German Invasion of France
A series of battles were fought along the borders between France and Belgium and France and Germany. Known as the Battle of the Frontiers, the offensives commenced with the Battle of the Marne on August 14, 1917. Over two million soldiers were involved in combat, making it the largest battle of its time.
The early invasions were accompanied by significant naval battles. The Battle of Heligoland Bight in August 1914 brought the two rival navies, the British Royal navy and the German Imperial Navy face-to-face. One significant outcome of the battle was the policy of unrestricted submarine warfare undertaken by Germany. This would ultimately lead to America’s entry into the war in 1917.
Germany shouldered the blame for World War I in the Paris Peace Conference of 1919. It must be said, though, that at the time of the first invasions, neither the Allied nor the Central nations had anticipated a war of the scale and duration as World War I.
Major Battles of World War I |
| Battle of Tannenberg – 1914 | Battles of Gaza – 1917 |
| Battle of Heligoland Bight – 1914 | Second Battle of Aisne – 1917 |
| First Battle of Marne – 1914 | Second Battle of Arras – 1917 |
| First Battle of the Masurian Lakes – 1914 | Battle of Messines – 1917 |
| First Battle of Aisne – 1914 | Battle of Passchendaele – 1917 |
| First Invasions of World War I | Battle of Caporetto – 1917 |
| First Battle of Arras – 1914 | Battle of Cambrai – 1917 |
| First Battle of Ypres – 1914 | German Spring Offensive – 1918 |
| Gallipoli Campaign – 1915 | Hundred Days Offensive – 1918 |
| Second Battle of the Masurian Lakes – 1915 | Battle of Mons – 1914 |
| Battles of Isonzo – 1915 | Second Battle of Somme – 1918 |
| Loos-Artois Offensive – 1915 | Second Battle of Marne – 1918 |
| Battle of Verdun – 1916 | Battle of St Mihiel – 1918 |
| Battle of Messines – 1917 | |
| First Invasions of World War I | Battle of Vittori Veneto – 1918 |
Major Treaties of World War I