As German troops move into Bulgaria, Yugoslavia becomes the key to the invasion of Greece. Hitler meets Prince Paul of Yugoslavia at Berchtesgaden to pressure him into joining the Tripartite Pact, offering the Greek Agean port of Salonika in return. Britain also seeks Yugoslavian assurances denying Germany access to Greece. Prince Paul must decide soon.
Transport of Allied troops and equipment from North Africa begins (Operation Lustre). 4 freighters depart Alexandria and Port Said, Egypt, escorted by destroyers HMS Hereward and HMS Stuart.
British General Wilson arrives in Athens to take command of Allied ground forces. He discovers confusion over the planned defense against German attack. Greek troops still hold the Metaxas line facing Bulgaria instead of withdrawing to the Aliakmon Line (as had been agreed, or so the British thought).
In Albania, Italian warships shell Greek coastal positions in preparation for a renewed Italian ground offensive.
Operation Claymore. At dawn, landing ships HMS Queen Emma and HMS Princess Beatrix land 500 British Commandos at 4 ports in the Lofoten Islands, Norway (escorted by destroyers HMS Somali, Bedouin, Tartar, Eskimo and Legion). They destroy fish oil factories and 3600 tons of fish oil (Germany extracts glycerine from fish oil, a vital ingredient in high explosives). 9 merchant ships are blown up by the Commandos or sunk by shellfire from the destroyers. Enigma cypher machine rotor wheels and code books are captured from German armed trawler Krebs, allowing cryoptographers at Bletchley Park to read the German naval codes (Krebs is then sunk). At 1 PM, the landing ships leave with all the Commandos, 228 German POWs and 314 Norwegian volunteers.
In the Indian Ocean South of the Seychelles, a Walrus seaplane from Australian cruiser HMAS Canberra spots German steamer Coburg and captured Norwegian tanker Ketty Brøvig (supply ships for German armed merchant cruisers). HMAS Canberra tries to intercept, but Coburg and Ketty Brøvig are scuttled to avoid capture.