The Battle of Liège was part of the Schlieffen plan as Germany feared a long two-front war against France and the Russian Empire, the Schlieffen plan was conceived which suggested a quick strike to beat France first. In order to do this neutral Belgium had to be crossed within a few days. The highly fortified city of Liège was in the path of the German forces as they advanced through Belgium.
War was declared on Belgium on the morning of 3 August, the lead elements of 'Army of the Meuse' crossed the border at 0800 on the 4th. The cavalry advanced to the Meuse river, but found that the bridges had been destroyed. By the late afternoon of 4 August, the German cavalry had crossed the Meuse to the north at Visé and encountered troops of the 12th Brigade, who had conducted a valiant retreat to the fortress line. German forces were held in check in the north for the night.
The Belgian 3rd Division guarded the town, on the same day they successfully repulsed attacks by German infantry passing between the forts. An attack against Fort Barchon was beaten back with heavy losses due to machine-gun and artillery fire. After this failed attack, the Germans carried out an air raid by using a Zeppelin to drop bombs on Liège. Meanwhile cavalry moved south from Visé to encircle the town. With the town likely to be invested soon, Leman ordered the 3rd Division to withdraw and rejoin the mobilizing Belgian army to the west.
With the fortifications in and around Liege which were causing heavy casualties to the Germans, the Germans would have to employ their massive seige artillery.
It is not clear what effect the ten day resistance in and around Liege by Leman and his troops had on the timetable of the German Schlieffen Plan. What is clear is that the battle was regarded as a moral victory by the Triple Entente.
France awarded the city of Liege with the Legion d'honneur in 1914.