World War One Diary for Wednesday, April 4, 1917:

Western Front

Artois: BEF 2,000-gun Arras barrage begins including gas shells, wreaks great destruction on 12­-mile front.

Aisne: German raiding party captures copy of division order at Mt Sapigneul giving movements of 3 corps on right of French Fifth Army. Nivelle told on April 7.

Sea War

North Sea: Royal Navy decides to convoy Scandinavian ships carrying imported wood pulp.

Western Mediterranean: British liner City of Paris (122 lives lost) sunk by UC 35 south off Nice.

Neutrals

USA: Senate votes war resolution 82-6.

Secret War

Switzerland: Lenin and Zürich councillor Platten negotiate with German Berne Ambassador Romberg.