The 73rd Light Anti-Aircraft Regiment (73rd LAA Rgt), was an air defence unit of the British Army's Royal Artillery during World War II.

It served during the London Blitz, landed on D-Day, seeing action throughout the campaign in North West Europe and defending the cities of Belgium against V-1 flying bombs.

In November this battery joined the regiment, replacing 221st Bty, which was transferred to a newly formed 97th LAA Rgt in 65th AA Brigade.

[1][7][8] In March 1942 the fourth Troop of each Battery was removed and constituted into a new 466th LAA Bty; this was mainly composed of men of low medical categories.

Anti-Aircraft Command had been increasing the LAA cover of the South Coast of England since the Luftwaffe began a campaign of 'hit and run' raids by fighter-bombers earlier in the year.

[9][11][12] On 10 December 1942, 73rd LAA Rgt was withdrawn from AA Command and joined Home Forces for advanced mobile training, which began round Ramsgate.

As a mobile unit, it consisted of three Batteries, each composed of three Troops equipped with six towed Bofors guns using 'Stiffkey Stick' sights.

[13][20] In February 1944, the regiment received six Crusader AA Mark I tracked self-propelled (SP) Bofors guns, which would have a special role in the assault landing on D-Day.

[21][22][23] Training continued through early 1944, with the regiment visiting No 16 AA Practice Camp at Clacton-on-Sea before moving to Slinfold in West Sussex.

Light AA defence was emphasised at the start of the operation, since low-level attack by Luftwaffe aircraft was considered the most likely threat and the designated assault regiments landed with minimum scales of equipment, to be brought up to strength by parties arriving later.

One troop of 296/73 LAA Bty was assigned to 'P' AA Assault Group on Juno Beach, the other was held in reserve in England.

220th Battery arrived late, found its intended positions to be still in enemy hands and could not begin landing until the following day (D+1) on Juno beach.

Luckily, Luftwaffe attacks on D-Day were few and sporadic, only increasing on D+1, by which time more guns of 73rd LAA Rgt had got ashore.

[20][21][27] At the end of August, 21st Army Group broke out from the Normandy beachhead and began to pursue the defeated German troops across Northern France.

73rd LAA Regiment reverted to mobile operations, with two towed and one SP battery, supported by the 30 three-tonner lorries of 1573 Platoon Royal Army Service Corps (RASC).

[21][31] The regiment's own transport platoon and 1573 Pln RASC then returned to help move up 4th Royal Marines LAA Rgt, which had just landed at Cherbourg Harbour, driving 1000 miles in total.

[21] 73rd LAA Regiment was withdrawn from Le Havre on 14 October and moved to Antwerp where it reverted to 80 AA Bde command once more.

Clearing the Scheldt Estuary and bringing the port of Antwerp into use as a supply base was an important element in the Overlord plan.

With 296th Battery returning to the Antwerp X defences, and the REME Workshop at the Scheldt, RHQ ended the year with no units under its direct command.

[20][21][33] On 1 January 1945, the Luftwaffe launched Operation Bodenplatte: daylight attacks by single-engined fighters against Allied airfields and lines of communication in support of the Ardennes offensive.