[4][12][13][14][15][16] For the projected attack on Narvik by Lt-Gen Claude Auchinleck's North Western Expeditionary Force in May, AA guns were landed at Harstad, an island base just outside Narvikfjord with an anchorage, and an airstrip in Skånland Municipality on the opposite coast.

[13][17] 6 AA Bde did not start to arrive until 6 May: 'As it came into action its guns were engaging enemy aircraft almost daily as aerial attacks were made in shipping in the fjord.

[2][3] During the Battle of Britain and the early part of The Blitz 51st HAA served in 48th AA Bde responsible for the air defence of London.

51st HAA Rgt reached Cairo on 16 October 1940 and came under the command of 4th AA Bde, assembling in the rear area ready to move up in the mobile role to support the WDF.

Unfortunately, the situation in the Greek Campaign deteriorated and on February 16 2nd Bty was recalled from Benghazi and had to drive back 736 miles to Egypt to embark for Greece.

151 (London) Battery was so reduced that shortly after the survivors reached Egypt GHQ Middle East ordered its disbandment, which was carried out on 1 July.

[2][26][27][28][29][30] On arrival at Tobruk, 51 HAA's workshop detachment set about restoring some of the captured Italian AA guns to working order, while the two batteries followed the WDF to Benghazi.

4th AA Brigade was a major element of the garrison, and had been reinforced just before the ring closed round Tobruk, with 235 (Kent) Battery of 89th (Cinque Ports) HAA Regiment arriving to replace 151 Bty.

On 14 April, Regimental HQ and 153 Bty were attacked by Stukas; Lt-Col McIntyre was among those wounded, and later that day RHQ was evacuated by sea to Alexandria.

[35] The regimental historian notes that these Stuka attacks concentrated on gun positions, which was a serious threat to HAA sites, whose instruments could not cope with the rapid height changes.

The gunners devised a tactic of opening fire with short fuzes just before the dive started, to force the pilots to fly through a ring of bursts.

In the last two months of the siege, troops of HAA guns took it in turn to move out to the perimeter and take on ground targets under the control of 9th Australian Division.

)[2][41][42] 51st HAA Regiment was assigned to 1st AA Bde in the rear of Eighth Army, guarding Benghazi and Agedabia and the landing strips nearby.

However, Eighth Army's supply base at Tripoli was badly bombed in March 1943 and 51st HAA was sent up to strengthen the air defences there under 2nd AA Bde.

By May 1943, 51st HAA had moved forward again, into Tunisia, and was part of 12th AA Bde, charged with defending advanced RAF airstrips, sometime only 2000 yards behind the front line and under regular air attack.

[43] The regiment remained under Middle East Forces during the Allied landings on Sicily,[4][12][44] but it rejoined Eighth Army for the Italian Campaign from September 1943 until the end of the war in Europe.

[4][12][45] The regiment was assigned to 2nd AA Bde on Sicily to protect Operation Baytown, the amphibious landing of XIII Corps on the Italian mainland.

[46] As the campaign developed, XIII Corps crossed to Bari on Italy's east coast, and then advanced to capture the airfield complex around Foggia.

During the winter of 1943–44 he disposed two-thirds of his HAA guns in the forward area, the rest at landing grounds as far back as Foggia, and he rotated batteries between the tasks.

[48] By August 1944 2nd AA Bde made a long march from Ancona to Anzio for refitting and training, but when the brigade returned to the front, 51 HAA was left behind to absorb African Other Ranks, who were replacing a proportion of the British personnel in a process known at the time as 'dilution'.

Due to the decline of the Luftwaffe, there was little air activity, and from Autumn 1944 the brigade's HAA guns were entirely committed to medium artillery tasks, engaging enemy ground positions with their 3.7-inch High Explosive ammunition.

The HAA units in this brigade also developed a technique known as 'Honey Combing': firing accurate air bursts over enemy AA positions to suppress them and enable Allied aircraft to operate safely in the area.

For example, in November 1944, 51 HAA had two batteries providing AA defence for Arezzo, and one operating in the field role with British XIII Corps in US Fifth Army.

As well as supporting these attacks, the regiment fired various tasks, including CM and bridge demolition, and against infantry formations, but found that the speed of the enemy withdrawal made it difficult to stay in range, and frequent moves forward were required.

[9] There is a memorial plaque to 51 HAA Regiment in St Luke's Church, Chelsea, carrying 96 names of men who died on service during World War II.