Battle of Vimy Ridge. British cavalry riding through the town of Arras, Lieutenant Ernest Brooks, 11 April 1917. Image courtesy Imperial War Museum © IWM (Q2825).
- At 4am Canadian troops on the Western Front launch their final assault in the Battle of Vimy Ridge. Battling snowfalls and strong westerly winds they engage in heavy fighting, capturing ‘The Pimple” [Hill 119] and 4,000 prisoners by nightfall. The Canadian Corps at Vimy capture more ground, more prisoners and more guns than any previous British offensive in two-and-a-half years of war. The capture of Vimy Ridge is the greatest Allied victory to date, but is not without its costs; the Canadian Corps sustains 3,598 killed and 7,004 wounded. Canadian Capture of Vimy Ridge
- Allied troops advance north of Vimy Ridge, taking Bois en Hache, Heninel and Wancourt
- Turkish forces in Mesopotamia retreat towards Deli Abbas on the Diyala River
- Costa Rica places its territorial waters and ports at the disposal of the United States of America
