Day 587 April 9, 1941

At 00.37 AM 400 miles Northeast of Canary Islands, U-107 sinks British SS Harparthian carrying RAF stores to Freetown, Sierra Leone (4 killed, 39 survivors make land at Hierro Island, Canary Islands). At 2.16 AM 200 miles Southeast of Iceland, U-98 sinks Dutch SS Prins Willem II (3 dead, 22 survivors in 2 lifeboats are picked up by Swedish steamer Klipparen and British MV Tuscan Star).

Greece. 2nd Panzer Division quickly moves South from Dojran Lake across the coastal plain to the major Greek port of Salonika on Agean Sea. In 4 days, they have outflanked Mataxas Line, isolating Greek forces in Macedonia and Thrace. In addition, German troops arrive at the Monastir Gap in Southern Yugoslavia ready to cross the unfortified border into Greece. This will allow them to cut off the main bulk of Greek Army facing the Italians in Albania and also to get behind the British & ANZAC forces in the Aliakmon Line defending against attack from Bulgaria.

Libya. Rommel orders Italian 27th "Brescia" Division and German 5th Light Division to surround Tobruk, realizing the urgency of attacking before the Allied defenses are organised. However, Australian 9th Division mans the outer defensive perimeter at Tobruk (originally created by the Italians) while a new inner defensive ring is built. Australian 7th Division is diverted from going to Greece, as planned; instead 18th Infantry Brigade is sent to assist at Tobruk while the remaining brigades are to defend Egypt.

In a sign of growing American involvement, the Danish colony of Greenland is made a US protectorate. Danish ambassador to the US, Henrik Kauffmann, signs the agreement on the anniversary of the German occupation of Denmark. Kauffmann will become known as "the King of Greenland".

Overnight, 237 Luftwaffe aircraft drop 285 tons high explosive bombs and 1,110 incendiary canisters on Birmingham in the English Midlands.