The battle of the Yser (18 October-30 November 1914) was the northernmost battle of the Race to the Sea, the series of battles which decided the location of the Western Front after the outbreak of trench warfare on the Aisne in early September 1914. The River Yser was a narrow river that runs into the North Sea close to Nieuport. It ran between high embankments designed to protect the surrounding low land around the river, with the western embankment higher than the eastern. Just to the west of the river the Dixmunde-Nieuport railway ran along its own embankment. The gap between the river and the railway would play an important role in the upcoming battle. Nieuport was the key to the line, as the sluice gates that could flood the surrounding areas were located there.
The Belgian army had started the war defending the great fortresses of Namur and Liege. After the fall of Liege, much of the army had retreated north to Antwerp. In early October they were then forced to retreat west from Antwerp, which fell to the Germans on 10 October. When the retreat ended on the River Yser, the army consisted of six infantry divisions, one cavalry division and the naval brigade, a total of around 65,000 men. During the battle they would be supported by a number of French units and by a Royal Navy squadron under Admiral Hood (two light cruisers, two monitors and a number of destroyers).
The battle began with an attack on the Belgian line by the German III Reserve corps, all along the line between Dixmunde and the sea. The Germans captured a number of Belgian bridgeheads on the eastern bank of the river, but were unable to cross the river.
A period of repeated German attacks followed. Dixmunde was attacked on 21 and 24 October, but remained in Belgian and French hands until 10 November. The German bombardments were supported by a number of 420mm howitzers previously used at Antwerp.
On 24 October two German divisions managed to get across the Yser. Over the next few days the German official history records that their artillery also crossed over the river, but a series of major attacks on 25 October failed. With the Germans across the river, the Belgians decided to flood the area between the river and the Dixmunde-Nieuport railway. A first attempt to open the Fumes lock at Nieuport on 27 October failed, but at high water on 28 October the lock gates were opened and the low lying ground east of the railway began to flood.
The Germans did eventually capture Dixmunde. On 10 November twenty German battalions attacked the four French and Belgian battalions in Dixmunde, forcing them to retreat west across the Yser, destroying the bridges behind them. Fighting continued along the Yser for much of the war, although without any major battles, until the Allied advance that ended the war.