Fourth Battle of Ypres
The Battle of the Lys (also known as the Lys Offensive, the Fourth Battle of Ypres and the Battle of Estaires) was part of the 1918 German offensive in Flanders during the First World War, originally planned by General Ludendorff as Operation George but scaled back to become Operation Georgette, with the objective of capturing Ypres. Starting on April 9, 1918, the battle lasted until April 29.
The German attack was able to smash through 2 Portuguese divisions. Although they captured some land, German forces were ultimately brought to a halt by French and British divisions. By April 29th Ludendorff ceased Georgette operations.
In one of the greatest failures in the military history of Portugal, the 2nd Portuguese Division, approximately 20,000 men commanded by General Gomes da Costa (later President of Portugal), lost about 300 officers and 7,000 men, killed, wounded and prisoners, resisting the attack of four German divisions, with 50,000 men of 6th German Army, commanded by General Ferdinand von Quast, in the first day of the German offensive.