UNITED KINGDOM: RAF Bomber Command: 4 Group (Whitley). Bombing - road/rail communications at Avesnes, La Capelle, Mons, Binche and the Ruhr. 10 Sqn. 12 aircraft. 11 bombed, one damaged by Flak and returned with hung-up bomb. 51 Sqn. 11 aircraft. Two aborted, eight bombed. 58 Sqn. Seven aircraft. All bombed, one damaged by Flak.

Anti-Aircraft cruiser HMS Bonaventure commissioned.

Corvette HMS Gardenia commissioned.

WESTERN FRONT: RN: During operations to support the BEF and French falling back on Dunkirk, French destroyers L'Adroit, Orage, Jaguar and Chacal are lost off the channel ports. W class destroyer HMS Wessex is bombed repeatedly and sunk off Calais at 51 00N, 16 37E,  as she supports the defenders. (Alex Gordon)(108)
The Royal Navy begins small evacuations today and will continue for two more days from Boulogne, France. This evacuation will lift 5,000 men to Britain.

FRANCE: Arras: Lt. the Honourable Christopher Furness (b.1912), Welsh Guards, died when, against hopeless odds, he led a successful delaying attack on the advancing Germans.

This morning 1 Panzer Div., establishes four bridgeheads on the east bank of Aa canal, at Holque, Saint-Pierre-Brouck, Saint-Nicolas, and Bourbourgville, south of Gravelines, which it could not capture. It is in a position to thrust towards Dunkirk, supported on the right by SS Regiment ‘Leibstandarte Adolf Hitler’, which Guderian had placed at Watten on the Aa, "to lend weight to the 1 Panzer attack on Dunkirk." For the same reason he orders 2 Panzer to send to Watten, all the units which can be spared from the investment of Boulogne.

GERMANY: Hitler issues his war directive number 13, ordering the annihilation of the Allies in Artois and Flanders and an aerial attack on Britain.
The OKW issues Führer Directive #13. 
(i) The next object of our operations is to annihilate enemy forces in Artois and Flanders by concentric attack and the rapid seizure of the Channel coast. The task of the Luftwaffe is to break resistance of surrounded forces, to prevent the escape of English forces across the Channel, and to protect the southern flank of Army Group A. The enemy air forces will be engaged at every opportunity. 
(ii) The remaining enemy forces in France will then be destroyed in the shortest possible time. Phase I will entail a thrust between the sea and the Oise towards the lower Seine. Phase II will be the main attack including strong armoured forces directed south-eastwards either side of Rheims, with the intention of defeating the main body of the French Army and bringing about the collapse of the Maginot Line. Phase III includes subsidiary attacks on the Maginot Line with the aim of breaking through the most vulnerable points. 
(iii) The Luftwaffe is now authorized to attack the English homeland. When sufficient forces are available the attack will open with an annihilating reprisal for the English attacks on the Ruhr. Air operations will continue in support of our forces in France, with the added aims of breaking up enemy reinforcements and hampering the re-grouping of enemy forces. Consideration should be given to strengthening air defenses in those areas where the enemy is concentrating his attacks. 
(iv) All restrictions on naval operations in French and English waters are now lifted. Kriegsmarine plans for the siege of England should be submitted to OKW. The Führer reserves the decision of announcing the form of the blockade. (Marc Roberts)

11.30 am - Hitler arrives at Rundstedt’s CP. According to the army group’s war diary: "he had the situation explained to him, and fully approved of the idea of keeping the Panzers on the line of the canals, in order to block the enemy and beat him once he has been defeated on the east by Group B. He insisted on the absolute necessity of saving the Panzers for ensuing operations, and of not pressing too hard on the surrounded Allies, which would have the undesirable effect of restricting the Luftwaffe’s field of action." Hence Hitler stops the Panzers at the gates of Dunkirk.