- King George V decrees that members of his family with a German surname are to adopt a British one. Those bearing the surname Teck adopt the surname Cambridge; those named Battenberg become Mountbatten.
- British troops on the Western Front advance at Arras
- Italian troops on the Southern Front continue their offensive on the Asiago plateau, gaining ground on Mount Ortigara
- General Sir Arthur William Currie is appointed commander of Canadian troops in France
General Sir Arthur William Currie, Commander of Canadian troops in France, June 1917. Image courtesy Library and Archives Canada.
