Operation Siege of Calais

The 'Siege of Calais' was the battle for the French port of Calais fought by German and Allied forces during the 'Battle of France' within the German 'Gelb' invasion of the Low Countries and France (22/26 May 1940).

The siege was fought at the same time as the 'Battle of Boulogne' and just before the 'Dynamo' evacuation of General the Lord Gort’s British Expeditionary Force and other Allied elements through Dunkirk. After the Franco-British counterattack in the 'Battle of Arras' on 21 May, German formations and units were held back to handle any resumption of the counterattack on 22 May, despite the protests of General Heinz Guderian, commander of the XIX Corps (mot.), who wanted to drive at speed to the north along the coast of the English Channel to take Boulogne, Calais and Dunkirk. An attack by part of the XIX Corps (mot.) was not authorised until 00.40 on the night of 21/22 May, however.

By the time Generalleutnant Ferdinand Schaal’s 10th Panzerdivision was ready to attack Calais, Brigadier C. N. Nicholsson’s British 30th Motor Brigade and the 3rd Royal Tank Regiment had reinforced the French and British troops holding the port. On 22 May, the British troops had established roadblocks outside the town and French rearguards skirmished with German armoured units as the latter advanced toward Calais. British tanks and infantry had been ordered farther to the south in order to reinforce Boulogne, but were too late to salve the situation. They then received orders to escort a food convoy to Dunkirk but found the road blocked by German troops. On 23 May, the British began to retire to the old walls of Calais and the siege began on 24 May. The attacks of the 10th Panzerdivision were for the most part costly failures, and by the evening the Germans reported that about half their tanks had been knocked out and one-third of the infantry were casualties. The German attacks were supported by the Luftwaffe, while the Allied defenders were supported by their navies delivering supplies, evacuating wounded and bombarding German targets around the port.

On the night of 24/25 May, the defenders were forced to withdraw from the southern part of the walled enceinte to a line covering the old town and citadel. Attacks on the following day against this shorter line were repulsed. The Germans tried several times to persuade the garrison to surrender but orders to hold had been received from London as an evacuation had been forbidden by the French commander of the northern ports. More German attacks early on 26 May failed and the German commander was given an ultimatum that if Calais was not captured by 14.00 the attackers would be pulled back and the town levelled by the Luftwaffe. The Anglo-French defences began to collapse early in the afternoon and at 16.00 the order 'every man for himself' was issued to the defenders, as Commandant Raymond Le Tellier, the French commander, surrendered. On the next day, small naval craft entered the harbour and extracted about 400 men, while aircraft of the RAF and Fleet Air Arm dropped supplies and attacked German artillery emplacements.

'Channel ports' in a phrase covering Boulogne, Calais, Dunkirk in north-eastern France and sometimes Ostend in Belgium. The ports are the nearest to Cap Gris Nez, the shortest crossing between France and England, and Calais is built on flat ground with low sand dunes on each side, and is enclosed by fortifications. There was a citadel in the old town surrounded by water and in 1940 on the eastern side the moat was still filled with water but elsewhere had become a dry ditch. Surrounding the town was an enceinte defensive fortification, which originally consisted of 12 bastions linked by a curtain wall, with a perimeter of 8 miles (13 km) and built by the great military engineer Sébastien Le Prestre de Vauban between 1667 and 1707.

In many places, the enceinte was overlooked by 19th-century suburban buildings. Two of the southern bastions and the wall linking them had been demolished to make way for railway lines leading to railway sidings and quays of the Gare Maritime in the harbour. About 1 mile (1.6 km) outside the enceinte to the west was Fort Nieulay. Two other forts to the south and east were derelict or had disappeared. Outside the town, the low ground to the east and south was cut by ditches, which limited the landward approach to roads raised above ground level. To the west and south-west, there is a ridge of higher ground between Calais and Boulogne, from which Calais is overlooked.

When plans for the deployment of the British Expeditionary Force were made, the Imperial General Staff drew on experience in World War I. The British Expeditionary Force had used the Channel ports as their entrepôts for supplies, even though they were only 20 miles (32 km) from the Western Front. Had the German spring offensive of 1918 succeeded in breaking through the front and capturing or even threatening the ports, the British Expeditionary Force would have found itself in a desperate position. During the period of the 'Phoney War' between 3 September 1939 and 10 May 1940, the British Expeditionary Force had been supplied through ports farther to the west, such as Le Havre and Cherbourg, but the Channel ports came into use once mine barrages had been laid in the English Channel late in 1939, to reduce the demand for ships and escorts.

On 10 May 1940, the Germans launched 'Gelb' as their offensive against the Netherlands, Belgium, Luxembourg and north-eastern France. Within a few days, Generaloberst Gerd von Rundstedt’s Heeresgruppe 'A' had broken through Général d’Armée André Corap’s 9ème Armée in the centre of the French front near Sedan and driven to the west down the Somme river valley led by General Ewald von Kleist’s Panzergruppe 'von Kleist' comprising Guderian’s XIX Corps (mot.) and Generalleutnant Georg-Hans Reinhardt’s XLI Corps (mot.). On 20 May, the Germans captured Abbeville at the mouth of the Somme river, cutting off the Allied troops in Belgium and north-eastern France. The 'Battle of Arras', a Franco-British counterattack on 21 May, led the Germans to continue to attack northward in the direct of the Channel ports, rather than advance southward over the Somme river. Apprehension about another Franco-British counter-attack led to the issue of the 'Arras halt order' issued the German high command on 21 May. General Hermann Hoth’s neighbouring XV Corps (mot.) was held back in reserve and one of the XLI Corps (mot.)'s divisions was moved to the east when the corps was only 31 miles (50 km) from Dunkirk.

Late on 21 May, the Oberkommando des Heeres rescinded the halt order, then instructing the Panzergruppe 'von Kleist' to resume the advance and move about 50 miles (80 km) to the north in order to take Boulogne and Calais. On the next day, Guderian gave orders for Generalleutnant Rudolf Veiel’s 2nd Panzerdivision to advance to Boulogne on a line from Baincthun to Samer, with Generallautnant Friedrich Kirchner’s 1st Panzerdivision as a flank guard on the right, advancing to Desvres and Marquise in case there was an Allied counterattack from Calais: the 1st Panzerdivision reached the vicinity of the port late in the afternoon. Schaal’s 10th Panzerdivision was detached to guard against a possible counterattack from the south. Parts of the 1st Panzerdivision and 2nd Panzerdivision were also held back to defend bridgeheads on the southern bank of the Somme river.

Calais had already been raided by Luftwaffe bombers several times, which caused disruption to military movements, confusion and traffic jams, with refugees making for Calais meeting refugees fleeing from the port. The French army units in Calais were commanded by Le Tellier, and the northernmost bastions and fortifications were manned by French naval reservists and volunteers commanded by the Commandant du Front de Mer (waterfront commander), Capitaine de Frégate Charles de Lambertye. Various army stragglers, including infantry and a machine gun company had also arrived in the town. On 19 May, Lieutenant General Sir Douglas Brownrigg, the Adjutant General of the British Expeditionary Force, appointed Colonel Rupert Holland to command the British troops in Calais and to arrange the evacuation of non-combatant personnel and wounded. The British contingent comprised one platoon of the Argyll and Sutherland Highlanders, which was guarding a radar site, the 2nd Anti-Aircraft Regiment Royal Artillery, the 58th (A&SH) Light Anti-Aircraft Regiment Royal Artillery and the 1st Searchlight Regiment Royal Artillery.

When the Germans captured Abbeville on 20 May, the War Office in the UK ordered the despatch of troops to the Channel ports as a precautionary measure. The 20th Guards Brigade was sent to Boulogne. The 3rd Royal Tank Regiment under Lieutenant Colonel R. Keller), the 1/Queen Victoria’s Rifles under Lieutenant Colonel J. A. M. Ellison-Macartney), the 229th Anti-Tank Battery Royal Artillery and the Nicolson’s new 30th Brigade were ordered to Calais. Most of the units sent to Calais were unprepared for action in some respects.

The 3rd Royal Tank Regiment was part of Brigadier J. T. Crocker’s 1st Heavy Armoured Brigade and had been about to leave for Cherbourg to join the 1st Armoured Division, which was assembling at Pacy-sur-Eure in Normandy. The brigade’s tanks had already been loaded aboard the transport City of Christchurch in Southampton. But during the night of 21/22 May at Fordingbridge, Keller received new orders to move the 3rd Royal Tank Regiment to Southampton, but during the journey the personnel train was diverted to Dover. Keller was briefed at Dover to go to Calais and given sealed orders for the British port commander (although he was not told who this was), and his men embarked on the transport Maid of Orleans.

The 1/Queen Victoria’s Rifles was a Territorial Army motorcycle battalion, nominally the divisional cavalry for the 56th Division. It had been attached briefly to the 30th Motor Brigade in April but was then returned to the 56th Division for home defence, losing its 22 scout cars. The battalion was stationed near Ashford in Kent and, late on 21 May, was ordered to proceed by train to Dover and embark for France. The motorcycle combinations and other vehicles were to be left behind. After a confused move it was realised that there had been a staff error and that there was room for the motorcycle combinations aboard City of Canterbury, but these did not arrive before the ship sailed.

Maid of Orleans and City of Canterbury carrying the personnel of the 3rd Royal Tank Regiment and 1/Queen Victoria’s Rifles departed Dover at 11.00 and reached Calais around 13.00 under a pall of smoke from buildings on fire in the town. The 1/Queen Victoria’s Rifles landed without motorcycles, transport or 3-in (76.2-mm) mortars and only smoke bombs for its 2-in (50.8-mm) mortars. Many of the men were armed only with revolvers and had to scavenge for rifles from those dumped on the quay by personnel hastily departing for England.

While they waited for their vehicles to arrive, the men of the 3rd Royal Tank Regiment were ordered to disperse in the sand dunes and were bombed soon after this. Keller met Holland, who told him to take orders from the general headquarters of the British Expeditionary Force, but at 17.00, Brownrigg arrived in Calais and ordered Keller to move the 3rd Royal Tank Regiment to the south-west as soon as it had unloaded, to join the 20th Guards Brigade at Boulogne. After Brownrigg had departed, Major Kenneth Bailey arrived from general headquarters with orders for the 3rd Royal Tank Regiment to go to St Omer and Hazebrouck, 29 miles (47 km) to the east of Boulogne, to make contact with general headquarters. Brownrigg had gone to Dover, unaware that his orders at Calais had been superseded. He met Nicholson and briefed him to relieve Boulogne with the 30th Brigade and the 3rd Royal Tank Regiment.

Carrying the 3rd Royal Tank Regiment’s tanks, City of Canterbury arrived from Southampton at 16.00, but unloading was very slow, as 7,000 Imp gal (32000 litres) of petrol had been loaded on deck and had to be moved using only the ship’s derricks as a power cut had immobilised the cranes on the docks. A power cut and a 4.5-hour strike by the ship’s crew during the night of 22/23 May added to the delay. The captain intended to leave the harbour without waiting, until he was held up at gunpoint by an officer of the 3rd Royal Tank Regiment. The dock workers were exhausted, having been at work unloading rations for the British Expeditionary Force for many hours, so it was not until the following morning that the vehicles had been unloaded and refuelled. The cruiser tanks had been loaded first and were therefore the last to be unloaded. Further delay was occasioned by the fact that the tank guns having been coated in a preservative and loaded separately, and had therefore to be cleaned before they could be remounted.

The 30th Motor Brigade had been formed on 24 April 1940 from the 1st Support Group to take part in the 'Norway Campaign'. After these orders had been cancelled, the brigade was posted to East Anglia to meet a supposed threat of invasion. The main body of the brigade comprised the 1/Rifle Brigade under Lieutenant Colonel Chandos Hoskyns and the 2/King’s Royal Rifle Corps under Lieutenant Colonel Euan Miller: these were both well-trained units, each about 750 men strong. Late on 21 May, they had been instructed to move by road to Southampton. They had arrived on 22 May and been embarked in a rather chaotic fashion: the vehicles were carried by Kohistan and City of Canterbury, which proceeded directly to Calais, the 2/King’s Royal Rifle Corps by Royal Daffodil and the 1/Rifle Brigade and the brigade headquarters by Archangel. They sailed on 23 May, at first for Dover, where they were joined by an 'auto carrier' containing the 229th Anti-Tank Battery Royal Artillery, which had moved from Sheffield but had been compelled to leave four of its 12 anti-tank guns behind as there was no room for them on the ship. The 30th Brigade’s personnel arrived at Calais during the afternoon of 23 May and then had to wait, like the 3rd Royal Tank Regiment, until the evening for the vehicle ships to arrive and be unloaded.

The 3rd Royal Tank Regiment had been assembling its 21 Light Tank Mk VI and 27 cruiser tanks at Coquelles on the road between Calais and Boulogne in accordance with the orders received from Brownrigg, and a patrol of light tanks was sent down the road to St Omer in accord with the orders received from general headquarters. The patrol found the town empty, under bombardment and illuminated by the fires of burning buildings, at which the patrol returned to Coquelles at about 08.00 in the morning of 23 May: the patrol was fortunate to have missed the 6th Panzerdivision, which had laagered for the night near Guînes, to the west of the St Omer road.

Calais was within the range of RAF aircraft based in England, and at 06.00 Hawker Hurricane single-engined fighters of No. 151 Squadron shot down a Junkers Ju 88 twin-engined medium bomber between Calais and Boulogne, and Supermarine Spitfire single-engined fighters of No. 74 Squadron shot down another Ju 88: both the German aircraft were machines of Oberst Alfred Bülowius’s Lehrgeschwader 1. Fighters of Nos 54 and 92 Squadrons claimed five Messerschmitt Bf 109 single-engined fighters of Oberstleutnant Max Ibel’s Jagdgeschwader 27 for the loss of one of their own number during the morning, and in the afternoon No. 92 Squadron lost two Spitfire fighters shot down by Messerschmitt Bf 110 twin-engined heavy fighters of Oberstleutnant Joachim-Friedrich Huth’s Zerstörergeschwader 26 'Horst Wessel' and Oberst Walter Grabmann’s ZG 76. On 21/22 May, LG 1 lost five aircraft over the Channel ports before the II/Jagdgeschwader 2 was assigned to the group as escorts, while JG 27 lost 10 Bf 109 fighters. Six British fighters were lost. Major Graf Clemens von Schönborn-Wiesentheid’s Sturzkampfgeschwader 77 lost five of its Junkers Ju 87 single-engined dive-bombers on this date. Air Vice Marshal J. M. Robb’s No. 2 Group of the RAF flew support sorties in the area from 21 to 25 May, losing 13 bombers.

The German advance was resumed in the morning and at 08,00 the German tanks crossed the Authie river. During the afternoon, French rearguards, with some parties of British and Belgian troops, were met at Desvres, Samer and the vicinity of Boulogne. The Allied air forces were active and made bombing and strafing attacks on the German forces, with little opposition from the Luftwaffe. The 10th Panzerdivision was released from its defensive role and Guderian ordered the 1st Panzerdivision, which was near Calais, to turn to the east in the direction of Dunkirk and the 10th Panzerdivision to move from Doullens to Samer and thence to Calais: the division had lost more than half its armoured vehicles and one-third of its transport to battle casualties, mechanical breakdown and attacks by RAF bombers since the 'Battle of Stonne' a week earlier, and Schaal complained that his division was tired but was over-ruled. The 1st Panzerdivision was to advance eastward to Gravelines at 10.00 on the next day. The 10th Panzerdivision's advance was delayed around Amiens because the infantry units which were to relieve the division in the bridgehead on the southern bank of the Somme river arrived late and the British reinforcements sent to Calais forestalled the Germans.

On 23 May, the threat to the German flanks at Cambrai and Arras had been contained and Generalmajor Wolfram Freiherr von Richthofen’s VII Fliegerkorps became available to support the 10th Panzerdivision at Calais. Most of the Ju 87 Stuka dive-bombers were based around St Quentin, after leap-frogging forward in the wake of the advance, but Calais was at the limit of their range. As units moved forward they had also come within the range of aircraft of Air Chief Marshal Sir Hugh Dowding’s RAF Fighter Command in England, and Richthofen assigned the I/JG 27 to St Omer for fighter cover. Among the Geschwadern (groups) flying in support of the 10th Panzerdivision were StG 77, Oberstleutnant Eberhard Baier’s StG 1, Oberstleutnant Oskar Dinort’s StG 2 'Immelmann' and the medium bombers of Oberst Dr Johan-Volkmar Fisser’s Kampfgeschwader 77.

The Luftwaffe units engaged RAF fighters and No. 92 Squadron shot down four Bf 109 fighters; three pilots of the I/JG 27 were taken prisoner, one was killed in action and No. 92 Squadron lost three Spitfire fighters and their pilots. To reinforce the German fighters, the I/JG 1, which was also based nearby to the south, was summoned to escort Ju 87 units attacking Calais. Flying from forward airfields at Monchy-Breton, Hauptmann Wilhelm Balthasar led JG 1 against the Spitfire fighters and claimed two of the four from his unit, but lost one pilot killed.

The 3rd Royal Tank Regiment received the report of the reconnaissance patrol and Bailey went back to general headquarters with a light tank escort. Bailey became separated from the escort and encountered the advanced guard of the 1st Panzerdivision at a crossroads on the St Omer road, and his driver was killed. The Germans were driven off by the men of a Royal Army Service Corps petrol convoy, which had arrived on the scene. Bailey and the wounded passenger returned to Calais at about 12.00 and told Keller that another attempt should be made as the Germans had pulled back. Keller had already received information from the French that German tanks were moving towards Calais from Marquise. Despite doubts, Keller sent the rest of the 3rd Royal Tank Regiment to follow the light tanks from Coquelles toward St Omer at 14.15. When about 1.25 miles (2 km) to the south-east of Hames-Bources, the rearguard tanks and anti-tank guns of the 1st Panzerdivision were spotted on the Pihen-les-Guînes road as they guarded the division’s rear of the division while the main body moved to the north-east in the direction of Gravelines.

The 3rd Royal Tank Regiment drove back German light tanks on the St Omer road but, despite losses, the heavier German tanks and anti-tank gun screen knocked out between seven ad 12 British tanks, before Nicholson ordered the 3rd Royal Tank Regiment back to Calais. Other units of the 1st Panzerdivision moving on Gravelines met about 50 men of C Troop, 1st Searchlight Regiment at Les Attaques, about 3.1 miles (5 km) to the south-east of Bastion 6 in Calais’s enceinte. C Troop had built a roadblock with a bus and a lorry, covered by Bren guns, rifles and Boys anti-tank rifles and held out for about three hours before being overrun. German tank and infantry parties then attacked a post at Le Colombier 1 mile (1.6 km) farther along the road between St Omer and Calais but were caught in crossfire from other posts and the guns of the 58th Light Anti-Aircraft Regiment on high ground near Boulogne. The Germans were repulsed until the post was withdrawn at 19.00. Calais was not the objective of the 1st Panzerdivision but Oberst Kruger, commanding the Kampfgruppe engaged at Guînes, Les Attaques and Le Colombier, had orders to take Calais from the south-east, if this could be achieved by a coup-de-main assault. As night fell the division reported that Calais was strongly held and broke off its attacks to resume the advance on Gravelines and Dunkirk.

Earlier, at 16.00, Schaal had ordered the main body of his 10th Panzerdivision, comprising the 90th Panzerregiment (two tank battalions) and 86th Schützenregiment (two infantry battalions) supported by a battalion of medium artillery, to advance up the main road from Marquise to the high ground around Coquelles, which would give them good observation over Calais. Meanwhile, on the right flank, a Kampfgruppe based on the division’s 86th Schützenregiment (two infantry battalions) was to advance from Guînes to the centre of Calais.

On arriving in Calais during the afternoon with the 30th Brigade, Nicholson had discovered that the 3rd Royal Tank Regiment had already been in action and had sustained considerable losses, and that the Germans were closing the port and had cut the routes to the south-east and south-west. Nicholson ordered the 1/Rifle Brigade to hold the outer ramparts on the east side of Calais and the 2/King’s Royal Rifle Corps to garrison the western side, behind the outposts of the 1/Queen Victoria’s Rifles and the anti-aircraft units outside the town, whose retirement to the enceinte began at about 15.00 and continued during the night. Just after 16.00, Nicholson received an order from the War Office to escort a truck convoy carrying 350,000 rations north-eastward to Dunkirk, and that this order was to supersede all other orders. Nicholson moved some troops from the defence perimeter to guard the Dunkirk road while the convoy assembled, but the 10th Panzerdivision arrived from the south and began to bombard Calais from the high ground.

At 23.00, the 3rd Royal Tank Regiment sent a patrol of a Cruiser Mk III and three light tanks to reconnoitre the convoy route, but the patrol ran into the 1st Panzerdivision's roadblocks covering the road to Gravelines. The tanks drove through the first barricade, then found many Germans beyond the third road block, who mistook the tanks for German, even when one of the tank commanders asked if they 'Parlez-vous Anglais?' The British tanks drove on for about 2 miles (3.2 km), were inspected by torchlight and then stopped at a bridge over the Marck river to clear a string of mines which had been laid across the road. Two mines were blown up by 2-pdr fire and the rest dragged clear, the tanks then becoming fouled by coils of anti-tank wire, which took 20 minutes to clear. The tanks drove on and reached the British garrison at Gravelines, but the radio in the Cruiser Mk III failed to transmit properly and Keller received only garbled fragments of messages, suggesting that the road was clear. A force of five tanks and a composite company of the 1/Rifle Brigade led the truck convoy at 04.00. Near Marck, about 3 miles (4.8 km) to the east of Calais, the British patrol encountered and outflanked a German roadblock, but at the break of day it was clear it would soon be surrounded and the patrol withdrew to Calais.

At 04.45 on 24 May, the French coastal guns opened fire and German artillery, and at dawn German mortar fire began falling on the port, and particularly French artillery positions, in preparation for an attack by the 10th Panzerdivision against the western and south-western segments of the perimeter. The retirement of the 1/Queen Victoria’s Rifles, and the searchlight and anti-aircraft troops, from the outlying roadblocks had continued through the night and up to about 08.30, when the troops had completed their withdrawal to the enceinte. Farther to the west, B Company of the 1/Queen Victoria’s Rifles was ordered back from Sangatte, about 5 miles (8 km) to the west of Calais, at 10.00 and had retired slowly to the western face of the enceinte by 22.00, and a C Company platoon out on a road to the east of Calais also stayed out until 22.00, but before 12.00 the main defensive line had been established on the enceinte. The first German attacks were repulsed except in the south, where the attackers penetrated the defences until forced back by a hasty counterattack by the 2/King’s Royal Rifle Corps and tanks of the 3rd Royal Tank Regiment. The German bombardment was extended to the harbour, where there was a hospital train full of wounded awaiting evacuation. The harbour control staff ordered the wounded to be put aboard the ships, which were still being unloaded of equipment for the infantry battalions and rear echelon of the tank regiment. The dock workers and rear-area troops were also embarked and the ships returned to England, with some of the equipment still on board.

During the afternoon the Germans attacked again, using armour-supported infantry, on all three sides of the perimeter. The French garrison of Fort Nieulay, outside the western ramparts, surrendered after a bombardment. French marines in Fort Lapin and the coastal artillery emplacements spiked their positions' guns and retreated. On the southern perimeter the Germans broke in again and could not be forced back, the defence being hampered by fifth columnists sniping from the town. The German troops who broke in began to fire in enfilade on the defenders from the houses they had captured. The defenders on the ramparts ran short of ammunition and the 229th Battery was reduced to two operational anti-tank guns. The Germans had great difficulty in identifying British defensive positions and, by 16.00, had managed only a short advance. At 19.00, the 10th Panzerdivision reported that one-third of its men, equipment and vehicles were casualties, together with half of its tanks.

The Royal Navy had continued to deliver stores and evacuate the wounded. The British destroyers Grafton, Greyhound, Wessex, Wolfhound and Verity, and the Polish destroyer Burza bombarded shore targets. The Ju 87 units made a maximum effort during the day: Wessex was sunk and Burza damaged by StG 2 and StG 77 during a raid at 16.42. StG 2 was ordered to target shipping. Dinort attacked Wessex but the destroyer made an elusive target and he missed after bombing on the second dive; the other two groups made a 40-strong formation which hit Wessex several times. The German crews had little training in anti-ship operations, but in the absence of British fighters dived from 12,000 ft (3660 m). As they departed, the dive-bombers came under attack by Spitfire fighters of No. 54 Squadron, which shot down three of the dive-bombers but lost three Spitfire fighters to the Bf 109 escorts.

Wolfhound put into Calais and her captain reported to the Admiralty that the Germans were in the southern part of town and that the situation was desperate. Nicholson had received a message from the War Office at 03.00 that Calais was to be evacuated and that as soon as unloading had been completed, non-combatants were to be embarked. At 18.00 Nicholson was told that the fighting troops would have to wait until 25 May. Lacking a reserve with which to counterattack on the perimeter, Nicholson ordered a retirement to the Marck canal and the Avenue Léon Gambetta, and during the night the defenders retreated to the old town and the area to the east, inside the outer ramparts and the Marck and Calais canals, while holding the north/south parts of the enceinte on both sides of the port. Le Tellier had set up the French headquarters in the cCitadel on the western side of the old town, but command of the French forces remained divided, with Lambertye still in charge of the naval artillery.

It had been arranged that French engineers would prepare the bridges over the canals for demolition, but this had not occurred and the British had no explosives with which to do it themselves. Nicholson was informed by a signal at 23.33 from General Sir Edmund Ironside, the Chief of the Imperial General Staff, that Général de Corps d’Armée Marie Bertrand Alfred Fagalde, the French commander of the Channel ports since 23 May, had forbidden an evacuation and that the defenders of Calais must comply. As the harbour had lost its significance, Nicholson was to choose the best position from which to continue the fight with forces who would receive more ammunition but no reinforcements. Nicholson was told that Major General A. F. A. N. Thorne’s 48th Division had begun to advance toward Calais to relieve the defenders. From 22.30 to 23.30, the French naval gunners spiked most of their guns and made their way to the docks to embark on French ships. Lambertye refused to go, despite being ill, and asked for volunteers from the 1,500 navy and army personnel to stay behind, about 50 men responding despite being warned that there would be no more rescue attempts. The volunteers took over Bastion No. 11 on the western side and held it for the duration of the siege.

During the night of 24/25 May, Vice Admiral Sir James Somerville crossed from England and met Nicholson, who said that with more guns he could hold on for a while longer, and the two men agreed that the ships in the port should return. At dawn on 25 May, the German bombardment resumed, concentrating on the old town, where buildings fell into streets, high winds fanned fires everywhere and smoke from explosions and the fires blocked the view. The last guns of the 229th Anti-Tank Battery were knocked out and only three tanks of the 3rd Royal Tank Regiment remained operational. Distribution of rations and ammunition was difficult, and after the mains had been broken, derelict wells were the only source of drinking water. At 09.00 Schaal sent the mayor, André Gerschell, to ask Nicholson to surrender, but the British officer refused to do so. At 12.00, Schaal offered another opportunity to surrender and extended his 13.00 deadline to 15.30 when he found that his emissaries had been delayed, only to be refused again. The German bombardment increased during the day, despite attempts by Allied ships to bombard German gun emplacements.

In the east, the 1/Rifle Brigade and parties of the 1/Queen Victoria’s Rifles on the outer ramparts and the Marck and Calais canals repulsed a determined attack. The French then eavesdropped on a German wireless message, which disclosed that the Germans were going to attack the perimeter on the western side, held by the 2/King’s Royal Rifle Corps. At 13.00, Nicholson ordered a counterattack and 11 Bren gun carriers and two tanks with the 1/Rifle Brigade were withdrawn and assembled for a sortie. The attackers were to depart from the enceinte in the area to the north of the Bassin des Chasses de l’Ouest and head at maximum speed round to the south to get behind the Germans. Hoskyns, commanders of the 1/Rifle Brigade, objected as the plan required the withdrawal of tanks and men from an area in which the Germans were close to breaking through. Hoskyns was overruled and it took too long to contact Nicholson, because telephone and radio communication had been lost. The attack went ahead but the carriers bogged in the sand and the attempt failed. At about 15.30, the units holding the Canal de Marck were overwhelmed and Hoskyns was wounded mortally by a mortar bomb. Major A. W. Allan, the 1/Rifle Brigade’s second in command, took over the battalion, which then made a fighting withdrawal to the north through the streets to the Bassin des Chasses, the Gare Maritime and the quays. In the south-eastern corner, at the 1/Rifle Brigade’s positions near the Quai de la Loire, a rearguard was surrounded and a counterattack to extricate it was repulsed. Some of the rearguard broke out in a van driven at gun point by a fifth columnist, but he stopped before reaching safety and few of the wounded reached cover. Only 30 of the 150 men in the area escaped.

The units of the 1/Rifle Brigade and1/Queen Victoria’s Rifles pulling back from the northern part of the enceinte gained a respite when German artillery mistakenly shelled the 2/69th Schützenregiment, which was forming in a small wood to the east of Bastion No. 2. In the afternoon, a German officer, together with a captured French officer and Belgian soldier, approached under a flag of truce to demand a surrender, which Nicholson again refused. The German attack was resumed and continued until the German commander decided that the defenders could not be defeated before dark. In the old town the 2/King’s Royal Rifle Corps and more parties of the 1/Queen Victoria’s Rifles fought to defend the three bridges into the old town from the south, but at 18.00 the German artillery ceased fire and Panzers attacked the bridges. Three tanks attacked Pont Faidherbe: two were knocked out and the third pulled back. At the Pont Richelieu, the middle bridge, the first tank drove over a mine and the attack failed. At Pont Freycinet, near the citadel, the attempt succeeded and the bridge was captured by tanks and infantry, who took cover in houses north of the bridge, until counterattacked by the 2/King’s Royal Rifle Corps. Parties of French and British troops held a bastion, the French in the citadel lost many men repulsing the attacks, and Nicholson established a joint headquarters with the French.

Shortly after Hoskyns had been mortally wounded, Keller, commanding the 3rd Royal Tank Regiment, decided that his few remaining tanks under shellfire near the Bastion de l’Estran could no longer play a useful part in the defence and therefore ordered them to withdraw to the east through the sand dunes to the north of the Bassin des Chasses, while he himself tried to evacuate 100 wounded men from Bastion No. 1 to the sand dunes; the wounded were captured a short time later. Riding on a light tank, Keller later reached C Company of the 1/Rifle Brigade to the north-east of the bassin, where he suggested that they and his tanks withdraw to Dunkirk, but his last tanks broke down or ran out of fuel and were destroyed by their crews. At the fall of night, Keller and some of the crews made their way on foot to Gravelines. Keller and one of his squadron commanders were able to cross the Aa river, and during the morning of the following day they made contact with French troops and were later evacuated to Dover.

At 10.30, No. 17 Squadron claimed three Stuka dive-bombers destroyed and three more damaged over Calais, as well asa Dornier Do 17 twin-engined light bomber. Air cover was maintained by No. 605 Squadron, which claimed four Ju 87 dive-bombers and one Henschel Hs 126 single-engined tactical reconnaissance aeroplane destroyed, together with another five unconfirmed claims, after an engagement at 17.54 while escorting a Bristol Blenheim twin-engined aeroplane on a reconnaissance sortie. The formation of 40 to 50 dive-bombers attacked shipping near the port. No. 264 Squadron flew escort operations in the afternoon without incident. On 25 May, Air Vice Marshal K. R. Park’s No. 11 Group flew 25 Blenheim bomber and 151 fighter sorties, losing two Blenheim aircraft and two fighters, against 25 Luftwaffe aircraft shot down and nine damaged to all causes. Air Marshal Sir Charles Portal’s RAF Bomber Command flew 139 sorties against land targets on 25 May. StG 2 lost four Ju 87 dive-bombers and had another damaged. All eight of the crews shot down were captured but released after the French surrender.

In case Fagalde reversed his 'no evacuation' order, 15 small naval vessels towing boats with room for about 1,800 men, waited offshore, some sailed into Calais harbour without an evacuation order and one vessel delivered another order for Nicholson to continue the battle. At 08.00 on 26 May, Nicholson reported to England that his men were exhausted, the last tanks had been knocked out, water was short and reinforcement probably futile, and also that the Germans had got into the northern end of the town. The resistance of the Calais garrison had led the German staff to meet late on 25 May, when Oberst Walther Nehring, the XIX Corps (mot.)'s chief-of-staff, suggested to Schaal that the final attack should be postponed until 27 May, when more dive-bombers would be available, but Schaal preferred to attack rather than give the British time to send reinforcements.

At 05.00, the German artillery resumed its bombardment. Several artillery units had been brought up from Boulogne, doubling the numbers of guns available to Schaal. From 08.30 to 09.00, the old town and citadel came under attack by artillery and up to 100 dive-bombers, after which the infantry attacked, while the German guns and the diver-bombers of the StG 77 and StG 2 subjected the citadel to heavy assaults for another 30 minutes. The 2/King’s Royal Rifle Corps continued to resist the German infantry attacks at the canal bridges. Schaal was informed that if the port had not been surrendered by 14.00, his division would be ordered back until the Luftwaffe had levelled the town. The Germans began to break through at about 13.30, when Bastion No. 11 was captured after the French volunteers had run out of ammunition. On the other side of the harbour, the 1/Rifle Brigade held its positions around the Gare Maritime while under attack from the south and east. Major Allan, in command, held on in the belief that the 2/King’s Royal Rifle Corps might withdraw to the north-east to the Place de Europe to make a joint final defence of the harbour. At 14.30, the Germans finally overran the Gare Maritime and the Bastion de l’Estran. The survivors of the 1/Rifle Brigade made a last stand on and around Bastion No. 1 before being overwhelmed at 15.30.

The 2/King’s Royal Rifle Corps retreated from the three bridges between the old and new towns, to a line from the harbour to the cathedral between the Rue Notre Dame and the Rue Maréchaux, 600 yards (550 m) from one of the bridges. Troops in the citadel began to show white flags. German tanks crossed the Pont Freycinet and British troops dispersed, having no weapons with which to engage armour. At 16.00, the new line collapsed and the 2/King’s Royal Rifle Corps was given the order 'every man for himself' after which only B Company fought as a unit, not having received orders to retreat to the harbour. The occupants of the citadel realised that the German artillery had ceased fire and found themselves surrounded at about 15.00, and a French officer then arrived with news that Le Tellier had surrendered.

During the day, the RAF flew 200 sorties near Calais, with six fighter losses suffered by No. 17 Squadron, which attacked dive-bombers of the StG 2, claiming three of them as well as a Do 17 and an Hs 126. Fleet Air Arm Fairey Swordfish single-engined bombers attacked German troops near Calais and the escort fighters of No. 54 Squadron claimed three Bf 110 and one Bf 109 fighter for the loss of three of its own aircraft. At 12.00, No. 605 Squadron claimed four Stuka dive-bombers of the StG 77] and one Hs 126 for a loss of a single Hurricane. The JG 2 protected the dive-bombers and fought off the attacks of No. 17 Squadron: there appear to have been no German losses, while the Germans shot down one Blenheim on a reconnaissance sortie. The I/JG 3 was able to conduct fighter sweeps over Calais after 12.00, with the battle almost over. Seven Bf 109 fighters engaged a flight of Hurricane fighters, the dogfight extending over Calais, and the British lost one Hurricane shot down for no loss to the JG 3.

It has been suggested that the defence of the advanced posts outside Calais by inexperienced British troops against larger numbers of German troops, may have deterred the commanders of the 1st Panzerdivision from probing the Calais defences further and capturing the port. In the early afternoon of 23 May, it was unlikely that the British troops on the Calais enceinte were prepared to receive an attack, the 2/King’s Royal Rifle Corps and 1/Rifle Brigade having disembarked only an hour earlier at 13.00. The unloading of the 2/King’s Royal Rifle Corps' vehicles was delayed until 17.00, and half of the battalion did not arrive at its positions until 18.00 to 18.30. An attack on Calais in the early afternoon would have been opposed only by the 1/Queen Victoria’s Rifles.

The day after the surrender of Calais, the first British personnel were evacuated from Dunkirk at the start of 'Dynamo'. In 1950, in response to the claim of Winston Churchill in Their Finest Hour that Adolf Hitler had ordered the German armour to stop outside Dunkirk in the hope that the British would make peace overtures, Guderian denied this and wrote that the defence of Calais was heroic but made no difference to the course of events at Dunkirk. The British official historian wrote that the defence of Calais and Boulogne diverted three Panzer divisions from the French 1ère Armée and the British Expeditionary Force; by the time that the Germans had captured the ports and reorganised, Lieutenant General Sir Ronald Adam’s III Corps had moved to the west and blocked the German routes toward Dunkirk.

The Franco-British counterattack at Arras on 21 May had achieved a disproportionate effect on the Germans as the latters' higher commanders were apprehensive about flank security. von Kleist, commander of the Panzergruppe 'von Kleist' perceived a 'serious threat' and informed Generaloberst Franz Halder, the chief of the Oberkommando des Heeres’s general staff, that he had to wait until the crisis was resolved before continuing. Generaloberst Günther von Kluge, command of the 4th Army, ordered the tanks to halt, an order supported by von Rundstedt, commander of Heeresgruppe 'A'. On 22 May, when the Anglo-French attack had been repulsed, von Rundstedt ordered that the situation at Arras must be restored before the Panzergruppe 'von Kleist' moved on Boulogne and Calais. At the Oberkommando der Wehrmacht the panic was worse and Hitler contacted Heeresgruppe 'A' on 22 May to order all mobile units to operate either side of Arras and farther to the west. and the infantry units to the east of the town.

The crisis among the German army’s higher staffs was not evident at the front, and Halder formed the same conclusion as Guderian, namely that the real threat was that the Allies would retreat to the English Channel coast, and a race for the Channel ports thus began. Guderian had ordered the 2nd Panzerdivision to capture Boulogne, the 1st Panzerdivision to take Calais and the 10th Panzerdivision to seize Dunkirk, before the halt order came. Most of the British Expeditionary Force and the French 1ère Armée were still some 60 miles (100 km) from the coast but despite delays, British troops were sent from England to Boulogne and Calais just in time to forestall the XIX Corps (mot.)'s Panzer divisions on 22 May. Had the German armour advanced at the same speed on 21 May as it had on 20 May, before the halt order stopped their advance for 24 hours, Boulogne and Calais would have fallen easily. Moreover, without the first halt at Montcornet on 15 May and the second halt on 21 May, after the 'Battle of Arras', the final halt order of 24 May would have been irrelevant as Dunkirk would already have fallen to the 10th Panzerdivision.

When the evacuation of troops was stopped, Vice Admiral B. H. Ramsay, the British naval commander in Dover, sent smaller craft to remove surplus men, and the launch Samois made four journeys to take wounded back to England. The yacht Conidaw entered Clais harbour on 26 May and ran aground, but was refloated on the afternoon tide and brought away 165 men, as other vessels took on more casualties. During the night of 26/27 May Ramsay had the motor yacht Gulzar painted with red crosses and sailed to Calais to recover wounded. At 02.00, Gulzar entered the harbour and docked at the Gare Maritime pier. A party went ashore and, on receiving fire, ran back and the boat cast off even as Gulzar was fired on from around the harbour. British troops on the eastern jetty called out and shone torches, which were seen by the crew: Gulzar turned back, and the fugitives jumped aboard as the yacht was still under fire, and thus escaped. On 27 May, the RAF responded to a War Office request of the previous evening to drop supplies to the Calais garrison and sent 12 Westland Lysander single-engined army co-operation aircraft to drop water at dawn. At 10.00, 17 Lysander aircraft dropped ammunition on the citadel, as nine Swordfish aircraft of the FAA bombed German artillery emplacements. Three Lysander machines were shot down and a Hawker Hector single-engined army co-operation biplane was damaged.