Britain: 22 Gotha bombers (1 lost) attack Sheerness and Shoeburyness (47 casualties). Only 5 out of 68 British fighters get within range, although 10 RNAS Dunkirk fighters attack formation on its way home after German fighters meet it.
Germany: The ‘Leader of U-boats’ Commander Bauer relieved of command. Bauer has advocated mass ‘wolf-pack’ tactics, ie using cargo submarine Deutschland as radio and fuel vessel for U-boat flotilla; U-66 is used (June 5-10) to try radio-location equipment but U-boats only work in pairs radioing convoy reports. Captain Andreas Michelsen replaces Bauer.
North Sea: Harwich Force (8 cruisers and 17 destroyers) covers Dover Patrol bombardment of Ostend by 2 monitors (20 of 115 shells land in or near dockyard damaging several craft), sinks German destroyer S-20 (9 survivors) and damages another. UC-70 also sunk, but raised to sink more ships. Royal Navy Air service bomb Ostend and Zeebrugge.
USA: Draft Registration Day for nearly 10 million men aged 21-31; 56,830 exemptions recognized including Quakers; 3,000 ‘slackers’ fled to Mexico.
Russia: Brusilov farewell to Southwest Front (200,000 men short) ‘I carry luck everywhere with me … now
I will lead all the armies of Russia to victory’.
Rumania: General Eben in command of German Ninth Army (until June 18, 1918) replacing Falkenhayn.