The Battle of Liège was the opening engagement of the German invasion of Belgium and the first battle of the First World War. The attack on Liège, a town protected by the Fortified position of Liège, a ring fortress built from the late 1880s to the early 1890s, began on 5 August 1914 and lasted until 16 August, when the last fort surrendered.

Germany had Belgium firmly in its sights. It needed to traverse Belgium in order to see its war plan against the French succeed. As more German troops poured into Luxembourg August 2nd, 1914, Belgium ordered its troops, which had already mobilized on July 31st, to be on guard and to defend its borders against any hostile forces. Belgium refused Germany’s “request” to allow it passage through Belgium, and the Germans ignored Belgium’s response.

Overall, the Battle slowed the Germans down by four or five days. This bought the French and English forces more time to mobilize. The location of the 12 forts ringing the city was evenly split between the banks of the Meuse River – six on one side, six on the other. Zeppelins were used to drop bombs on Liège and its Citadel. Field Marshal Karl von Bulow was the man in charge of the German 2nd army laying siege to Liège. The German siege cannon, a massive 42 centimeters (16.5 inches), was the largest land gun up to that point.

More Info: en.wikipedia.org