The Siege of Antwerp was a battle fought on the Western Front of World War I between the German Imperial Army and the Entente forces of Great Britain and Belgium. The Germans besieged the Belgian army and the British Royal Naval Division in the Antwerp area, after the German invasion of Belgium. With no hope of holding Antwerp, the Belgian army withdrew towards the Yser river. In the Battle of the Yser, close to the French border, the Belgians held out against the German onslaught and defended the last part of unoccupied Belgium. The Belgians held the area until late 1918, when they participated in the liberation of Belgium.