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WWII On This Day: May 18

What happened on May 18 during World War II? This date brings together 2 events from 1941 and 1942, with period photographs and links to the full operations documented across WW2 Theatres.

1941
The German battleship Bismarck in Grimstadfjord near Bergen on 21 May 1941, photographed from Prinz Eugen before the Atlantic breakout.
Naval History and Heritage Command · Public domain
The Bismarck Chase

Operation Rheinübung begins

Bismarck and Prinz Eugen sailed from the Baltic for a commerce-raiding sortie into the North Atlantic. Admiral Günther Lütjens was expected to reach the convoy routes without accepting unnecessary battle against equal British heavy forces. The operation began with an inherent constraint: Bismarck needed freedom to manoeuvre and access to fuel. The larger German surface force originally envisaged was unavailable, leaving the battleship and heavy cruiser to break out as a pair.

Continue in The Bismarck Chase →
1942
USS Yorktown under attack by Japanese torpedo bombers during the Battle of Midway, 4 June 1942.
USS Yorktown under torpedo attack, 4 June 1942 · US Navy · NARA · Public domain · Source
The Battle of Midway

AF is Midway

Station HYPO had been reading enough of the Japanese fleet code to know a major operation was coming against a target the signals called AF. Washington thought AF was somewhere else. Commander Joseph Rochefort's team proposed a test: have Midway transmit in the clear that its fresh water distillation plant had broken down. Two days later Japanese signals reported that AF was short of fresh water. The objective, the approximate date and much of the order of battle followed from that.

Continue in The Battle of Midway →