UNITED KINGDOM: RAF Bomber Command: 4 Group (Whitley). Bombing - oil refinery at Hanover. 51 Sqn. Four aircraft. Three bombed, one FTR. 58 Sqn. Four aircraft. Three bombed. 77 Sqn. Seven aircraft. Six bombed, one shot down by Bf110, crew rescued. Bf110 claimed destroyed. 102 Sqn. Eight aircraft. Seven bombed.

2 Group: 15 Sqn ( Blenheim) 6 aircraft to attack columns approaching Le Cateaux and destroy a bridge there. 3 aircraft FTR. 40 Sqn. Flew from Abbeville to bomb troops near Landacres meeting little opposition.

NORWEGIAN CAMPAIGN: (Mark Horan) HMS Ark Royal continued to maintain the fighter patrols over the convoy, dispatching sections at 0030 and 0300. The former, three Skuas of 800 Squadron, chased off a single He-111 with damage, the only interception of the entire affair.

At 1700, Ark reaches position 70.06N, 13.16E. At 1710 and 1830 Ark dispatched Skua sections to patrol Narvik, but neither sighted enemy aircraft. Meanwhile, at 1810, the three Royal Navy carriers joined forces, the first time in the war that three carriers had operated together.

HMS Glorious then flew off the remaining five Walrus amphibians of 701 Squadron to Flag Officer Narvik at Harstad, while Ark sent off a single Swordfish to photograph the conditions at Bardufoss landing ground.

Cruiser HMS Effingham goes aground on a rock pinnacle in the Norwegian Sea off Narvik at 67 17N 13 58E. A subsequent investigation showed that the marked position of the rock had been obscured by a thick pencil marking. After salvaging usable equipment, Effingham is destroyed by gunfire on 21 May. (Alex Gordon)(108)

Battleship HMS Resolution was badly damaged by one 1000-kg bomb during an attack by German Ju88 aircraft of II/KG 30 off Narvik. The bomb penetrated three decks before detonating.

WESTERN FRONT: The Wehrmacht High Command announced:

Enemy air assaults have been aimed at various cities along the North German coast, especially Hamburg and Bremen, and at cities in West Germany. As in all previous instances, the attacks were made indiscriminately on non-military targets, except for one military barracks. The German Wehrmacht High Command makes this point expressly, in the light of the consequences that are to follow.

BELGIUM: Antwerp capitulates.

Bruges: King Leopold has set up an improvised HQ in a remote chateau at Bruges, a few miles from the coast at Ostend. The atmosphere is sombre. The Germans have in Brussels; Antwerp is about to fall; the French in panic over the Sedan breakthrough, have begun withdrawing their forces from the Belgian front without informing the British or the Belgians; and the roads of Belgium and northern France are choked with refugees.

Lord Gort, the BEF commander, learned of the French decision by chance when a British officer visiting General Billotte’s First Army Group HQ noticed a message awaiting dispatch. The Belgians were told the following day. "It came like a shout out of the blue," says General Olivier Derousseaux, Leopold’s deputy chief of staff. "We had to shake ourselves back into action."

The British and Belgian armies began withdrawing along a 50 mile front without interference from the enemy, most of the Panzers having been taken south to the Sedan sector. But the French 7th Army, pulling back from the mouth of the Scheldt, cut through the British and Belgian lines, causing chaos.

FRANCE: At dawn, the Panzer Divisions, now set free by their High Command, cross the Sambre Canal, towards Le Cateau, and the Oise, towards Saint-Quentin. In the north, after an encounter with Char-B tanks held him up all morning in the Le Cateau area, Rommel seizes Cambrai in the afternoon.

In the south, the 2nd Panzers capture Saint-Quentin at 9 am. The 1st Panzers on their left push on towards Peronne and its bridges, which it seizes from local troops at 1 pm. and then sends out patrols on the left bank of the Somme as far as Chaulnes.

Now that the German Panzers have broken out of their bridgeheads over the River Meuse and are advancing west, the Allied command and control system is becoming increasingly numbed. The Blitzkrieg which overcame the Poles is in danger of doing the same to the British and French. The French High Command is sending out orders which are out of date. At 9.45 am, when the enemy was already at Saint-Quentin, Giraud addressed an order to his Army according to which "his instructions had not changed: the Sambre Canal (and the Oise) must be held, at the same time the area west of the canal must be cleared of the enemy which had infiltrated between Saint-Quentin, Bohain and Solesmes". Similarly, at GHQ in the morning, "the impression was that things were better," wrote the Chief of Staff. Road and rail communications were working smoothly, and they still believed in containing the enemy in a pocket and being able to patch up the front.

At 10 pm Reinhardt’s Panzer’s fell upon Le Catelet, where 9 Army’s CP was set up, and dispersed it. Later the commander of 9 Army, General Giraud, is captured.

At the end of the day Georges realises how impossible it is to contain the enemy on the Cambrai-Saint-Quentin line. He therefore orders the "2nd Region" to block the crossings on the Somme, west of Peronne, and to give the defence posts artillery support.

Then at 11pm in his Order No. 122, he made this decision. "In the eventuality of the westward thrust of the German armour, towards the Maubeuge-Peronne front, not being stopped head-on we must prepare for the extension of our barrier over the whole length of the Somme, from Peronne to the sea. The 7 Army must try to erect this barrier on the Crozat Canal and the Somme from Ham to Amiens. The barrier would be prolonged from Amiens to the sea."

In the evening, Billotte orders the withdrawal of Belgian, British and French armies to the line of the lower Escaut and Dender: on the canal from Terneuzen, middle Escaut at Ghent, Valenciennes, Bouchain.

Arras: British forces in Belgium and northern France, threatened by the sweep of Panzers towards the Channel and by the disintegration of the French 1st Army, are planning a counter-attack against the 7th Panzer and the motorised SS Totenkopf divisions near Arras.