April 17 1918, Merckem [Merkem]–Although over 90% of their country was occupied by the Germans, the Belgian Army still continued to defend their portion of the line in Flanders. Their sector had been relatively quiet since 1914, aided by deliberate flooding of much of the low-lying land in the area. Although officially not part of the Allies, the Belgians still did their best to cooperate with the forces that were helping to defend what remained of unoccupied Belgium from the Germans. When the Germans broke through south of Ypres on April 9, Belgian King Albert volunteered to extend his line south to aid the Allies.
On April 17, the Germans attacked the Belgian lines around Merckem, at the northern end of the Ypres Salient, which had been much reduced by Plumer’s withdrawal from Passchendaele. An attempted attack on the British lines the previous day had failed after the Germans realized they were attacking into nothing. Simultaneously, the Germans were attacking south of Ypres, towards Mt. Kemmel, in an attempt to take the high ground there and cut off what remained of the Ypres Salient.
The Germans had some initial success against the Belgians, but a counterattack with bayonets by the 3rd Division reversed all the German gains and captured 800 PoWs and 42 machine guns. The northern end of the Ypres Salient was secured, and the Belgians had won one of their first victories in Europe since 1914.
A French armored car arrives to assist British forces near Méteren, to the south of Ypres, on April 16.
April 15 1918, Passchendaele–The German advance in Flanders had slowed as the British had been able to scrape up reinforcements from wherever they could find them. However, the slackening of the German pace was not obvious to the British commanders, who were still far too short on reserves for comfort. Furthermore, Foch seemed reluctant to commit any French troops to the battle, and they knew the Germans had enough reserves to attack again elsewhere at almost any time. The German advance south of Ypres placed the British position in the Ypres Salient in a precarious position–and in fact the Germans were planning a new attack in the north to try to cut it off. With great reluctance, Plumer ordered a withdrawal from Passchendaele Ridge–voluntarily giving up what had been won with a cost of over 250,000 casualties last fall.
On April 15, most of the British forces on Passchendaele Ridge fell back to lines much closer to Ypres, while a much smaller force manning outposts along the original front line attempted to make it seem like nothing had changed. Those men withdrew as well that night, without the Germans noticing. The British were able to substantially shorten their lines and free up divisions to reinforce other areas of the front; they were soon aided by the Belgians, who agreed to extend their line, and the French, who finally committed troops to the battle after Foch saw how desperate Plumer’s situation was. The Germans would still make some gains to the south of Ypres over the next few days but they were quickly nearing the end of their rope; on the same day the British were evacuating Passchendaele, Crown Prince Rupprecht reported that “we are all utterly exhausted and burned out….Everywhere I heard complains of the accommodation of man and horse in the totally ravaged country and the heavy losses from bombs, particularly in horses which could not be hidden from sight.”
Troops of the York and Lancaster Regiment receiving instructions in the trenches before starting out on a patrol near Roclincourt, 12 January 1918. Note the rudimentary camouflage the patrol is wearing.