'Windsor' was a British offensive by Lieutenant General Sir Miles Dempsey’s 2^nd Army of General Sir Bernard Montgomery’s Allied 12^th Army Group round the western side of the city of Caen in the Allied lodgement in Normandy following 'Overlord' (4/5 July 1944).

The operation was centred on the urgent need to take Carpiquet airfield, to the west of Caen, by Major General R. F. L. Keller’s Canadian 3^rd Division of Lieutenant General G. G. Simonds’s Canadian II Corps. The capture of Carpiquet airfield had been one of the objectives initially allocated to 'Epsom', but was then postponed. On 1 July the capture of Carpiquet was then ordered for 4 July in 'Windsor', with 'Charnwood' for the seizure of Caen just to the east following about four days later. By this time Major General L. O. Lyne’s 59^th Division would have landed in Normandy and been readied to take part in the undertaking alongside Major General L. G. Whistler’s 3^rd Division and the Canadian 3^rd Division.

Caen had been a major first-day objective in 'Overlord' for Lieutenant General J. T. Crocker’s British I Corps of the 2^nd Army, which on 6 June had landed the British 3^rd Division on Sword Beach and the Canadian 3^rd Division on 'Juno' Beach with the express intention of taking Caen and Carpiquet airfield just to its west. German resistance prevented the town’s first-day capture, an outcome which had in fact been considered a possibility by Dempsey. For the next three weeks the Normandy lodgement was the scene of essentially positional warfare as each side on the 2^nd Army’s front attacked and counterattacked for minor tactical advantage.

On 26/30 June the 2^nd Army had undertaken 'Epsom' using Lieutenant General Sir Richard O’Connor’s newly arrived VIII Corps in an effort to outflank Caen and seize the high ground near Bretteville sur Laize to the south of the city. By the end of the operation, the VIII Corps had managed to advance 6 miles (10 km) through extensive field fortifications before the Germans had been able to check the offensive after committing their last reserves.

Depending on the success of the VIII Corps, the Canadian 3^rd Division, supported by Brigadier R. A. Wyman’s Canadian 2^nd Armoured Brigade, was to take the village and airfield of Carpiquet in 'Ottawa', an undertaking which was then postponed.

Even though British and Canadian forces had achieved penetrations in the area to the west of Caen, the formations of SS-Oberstgruppenführer und Generaloberst der Waffen-SS Josef Dietrich’s I SS Panzerkorps still held positions to the north and west of Caen. The German defences along the Orne river and in the vicinity of Carpiquet prevented any farther advance toward Caen from the north and, lying some 3.5 miles (5.6 km) to the west of the centre of Caen, Carpiquet now became an objective of the Canadian 3^rd Division.

The need for additional airfields in the Normandy lodgement made Carpiquet an invaluable prize for the Allies and an important defensive position for the Germans. Given the fact that each side considered the Carpiquet area to be strategically important, the German defences were formidable. Those at Carpiquet airfield were based on a 1.2-mile (1.9-km) expanse of level ground, which offered the defenders a perfect 'killing ground': the airfield itself was heavily protected with minefields, field gun and machine gun emplacements manned by the 1/26^th SS Panzergrenadierregiment and a Flak battery, and was supported by 15 tanks.

To take the lead in 'Windsor', Keller selected Brigadier K. G. Blackader’s Canadian 8^th Brigade, whose constituent battalions were the The Queen’s Own Rifles of Canada, Le Régiment de la Chaudière and The North Shore (New Brunswick) Regiment, bolstered by The Royal Winnipeg Rifles of Brigadier H. W. Foster’s Canadian 7^th Brigade, which was in fact earmarked to lead the assault. Armoured and machine gun support was entrusted to the Canadian 10^th Armoured Regiment (The Fort Garry Horse), The Sherbrooke Fusiliers and the Cameron Highlanders Support Battalion. Additional firepower was later added by two squadrons of Hawker Typhoon fighter-bombers and three squadrons of specialised tanks provided by Major General Sir Percy Hobart’s British 79^th Armoured Division. To add heavy artillery firepower to the initial bombardment, the 16-in (406-mm) guns of the battleship Rodney were to drop 15 rounds on the German positions around Carpiquet, some 15 miles (24 km) inland of the British capital ship.

The operation was to start from the area of Marcelet, which was held by Brigadier G. F. Johnson’s 32^nd Guards Brigade under the command of Major General G. I. Thomas’s British 43^rd Division. To prevent any German interference from the south, Brigadier H. Essame’s 214^th Brigade of the same division temporarily occupied Verson and the next village on the Odon river without incident in the course of the night 3/4 July.

'Windsor' was to be launched at 05.00 on 4 July after a major artillery bombardment. Le Régiment de la Chaudière and The North Shore Regiment were to attack Carpiquet while The Sherbrooke Fusiliers protected their northern flank. To the south, the RWR was to advance and seize the hangars of Carpiquet airfield. Once the two battalions had captured Carpiquet, the RWR was to drive through to seize the airfield’s control buildings, completing an undertaking which would facilitate further British and Canadian attacks on Caen.

At dawn on 4 July, the guns of 21 artillery regiments opened fire on German positions in and around Carpiquet, firing a creeping barrage 1 mile (1.6 km) wide and 400 yards (370 m) deep. At 05.00 two Canadian infantry battalions advanced on Carpiquet, while The Sherbrooke Fusiliers attacked to the north.The Sherbrooke Fusiliers broke through the German minefields, but the defensive positions of the 1/26^th SS Panzergrenadierregiment remained intact and continued to fire on The North Shore Regiment. In the centre, Le Régiment de la Chaudière avoided much of the fire directed at The North Shore Regiment as it advanced on Carpiquet. By 06.32 both battalions had reached the outskirts of the town, coming into contact with elements of SS-Brigadeführer und Generalmajor der Waffen-SS Kurt Meyer’s 12^th SS Panzerdivision 'Hitlerjugend', another component of the I SS Panzerkorps.

As the fighting in Carpiquet became a house-to-house battle of attrition, tanks of the Canadian 10^th Armoured Regiment assisted the infantry in gradually overcoming the German opposition. To the south, the RWR advanced slowly toward the airfield as the Germans made skilful use of their mortars to inflict many casualties on advancing infantry and armour. As a result it took the RWR some 90 minutes to advance the 1.5 miles (2.4 km) between Marcelet and the airfield’s hangar area. Only with eventual indirect fire support of a squadron of the 10^th Armoured Regiment was the RWR able to advance to the airfield. Several Sherman tanks were knocked out, and by 12.00 the RWR had been compelled to withdraw half-way toward its original line. Unaware that the RWR had failed to gain control of the airfield, Keller now committed the QRC to the second phase of the assault. The regiment moved forward into Carpiquet, now controlled by Le Régiment de la Chaudière and The North Shore Regiment, which attacked German strongpoints bypassed by the initial assault.

It took a combination of infantry attacks, flame-throwers, petard tanks (Churchill vehicles each fitted with an 11-in/279-mm spigot mortar) and the immolation of one strongpoint to force the remaining 12 defenders to surrender, with the rest surrendering after vicious fighting. The QRC reached the edge of Carpiquet as the RWR was withdrawing, and was ordered to hold the position until the RWR could reorganise for a second attack. For this renewed attack, Keller secured the assistance of two squadrons of Hawker Typhoon fighter-bombers, of Air Vice Marshal H. Broadhurst’s No. 83 Group, to support the attacks against positions of the 12^th SS Panzerdivision.

The remnants of the RWR were ordered to penetrate round the Germans' left flank through lower ground with the aid of armour and artillery support. In the late afternoon, the RWR resumed the attack on the airfield, and although it did manage to reach the hangar area, it was still not able to dislodge the German defenders. Now facing a German armoured counterattack, the RWR was ordered to withdraw to its start line under the cover of darkness.

In Carpiquet, three battalions of the Canadian 8^th Brigade rapidly fortified their positions. Following their seizure of the town, the Canadian 8^th Brigade was now positioned closer to Caen than any other element of the British 2^nd Army. Although the Canadians had firm control of Carpiquet and the northern hangar area, the southern hangar area and the control buildings remained in German hands. Less than 1 mile (1.6 km) from the outskirts of Caen, the Canadian 8^th Brigade was a serious threat to the German positions in the city. With most of their defence concentrated to the north of Caen and along the Odon river, the Germans feared that Anglo-Canadian forces could attack from Carpiquet and bypass the majority of the defences. Despite growing misgivings about the likelihood of a counterattack’s success, Meyer ordered the 12^th SS Panzerdivision to retake Carpiquet in co-operation with units of SS-Brigadeführer Theodor Wisch’s 1^st SS Panzerdivision 'Leibstandarte SS Adolf Hitler' prepared to counterattack toward Carpiquet from Francqueville with armour, artillery, mortars and infantry.

It was just after 24.00 that the first Waffen-SS counterattack began. Although it had lost 13 tanks on the previous day, the Canadian 10^th Armoured Regiment, supported by the mortars of The Cameron Highlanders of Canada, prevented the German armour from penetrating into the ruins of Carpiquet, and the Canadian defensive positions and machine gun fire inflicted heavy losses on the Germans. By dawn the Germans had retaken almost no ground, and by 12.00, with artillery and Typhoon fighter-bomber support, the Canadian 8^th Brigade and Canadian 10^th Armoured Regiment had defeated three counterattacks, in the process ensuring that German forces could not breach the Canadian positions. Before 12.00 General Heinrich Eberbach’s Panzergruppe 'West' had to report to Generalfeldmarschall Erwin Rommel’s Heeresgruppe 'B' that the attempt to recapture Carpiquet airfield had failed.

The surviving German forces withdrew, but the Canadians postponed any further attempt to complete the airfield’s capture until 8 July within the overall 'Charnwood' operation. The ruins of the village remained under Canadian control, even though German Nebelwerfer multi-tube rocket launchers and mortars continued to bombard Carpiquet.

Three days after 'Windsor' the British 2^nd Army renewed its efforts to take Caen, with the Canadian 3^rd Division taking part, in 'Charnwood'. On 9 July the Canadian 8^th Brigade captured Carpiquet airfield as 450 British aircraft bombed Caen in preparation for a full ground assault. By the end of the day, the British had taken the northern half of Caen, and the southern half had been flattened.

On 18 July British and Canadian forces launched 'Atlantic' and 'Goodwood' (i), the Canadians liberating the remainder of Caen in the former and the British securing terrain to the east and south of the city. Canadian forces then attacked German positions on Verrières Ridge.

Canadian casualties for the operation had been 127 dead and 250 wounded: most of these losses occurred on 4 July in the ranks of the RWR and The North Shore Regiment. The Canadian 10^th Armoured Regiment lost 17 tanks, but the losses of The Sherbrooke Fusiliers are not known. The 1/26^th Panzergrenadierregiment of the 12^th SS Panzerdivision lost 155 men, and the 1^st SS Panzerdivision lost about 20 tanks, as well as 115 men killed, wounded and missing from the ranks of its 3/1^st Panzergrenadierregiment.