North Sea – First Q-ship success: U40 torpedoed and sunk off Aberdeen by British submarine C26, towed in action by decoy trawler Q-ship Taranaki.
FIRST MAIN BATTLE OF THE ISONZO (CASTELNUOVO) until July 5 begins with a week’s Italian artillery bombardment: 75 Italian battalions and 530 guns against 40 Austrian battalions with 242 guns. Attacks on Podgora, Oslavice and Peuma fail until June 26, as does assault on the Sabatino on June 29-30.
Colonel Knox cables London that lack of rifles makes Russian offensive impossible for eight months.
East Africa: British Voi-Maktau railway completed (and water pipeline) despite German sabotage on June 14.
Britain: German spy Karl Müller shot at the Tower.
Prince of Wales’ 18th birthday.