The 79th (Hertfordshire Yeomanry) Heavy Anti-Aircraft Regiment, Royal Artillery (79th (HY) HAA Rgt) was an air defence unit of Britain's Territorial Army (TA).

Formed just before World War II, it fought in the Battle of France, the Swansea Blitz, Operation Torch and the Italian Campaign.

[5][6][11] In June 1939, as the international situation worsened, a partial mobilisation of Anti-Aircraft Command was begun in a process known as 'couverture', whereby each TA AA unit did a month's tour of duty in rotation to man selected gun positions.

[12][13] 79th (HY) AA Regiment was embodied on 25 June for a partial deployment to gunsites along the south bank of the Thames Estuary, with RHQ at Fort Borstal.

[16][17][18][19] The regiment's immediate task was to deploy two sections to defend Fighter Command's HQ at Bentley Priory near Stanmore in Middlesex.

During the autumn 79th (HY) AA Rgt handed over most of its responsibilities for airfields, and shifted towards the Gun Defence Area (GDA) round the port of Harwich and adjacent harbours, where Lt-Col Bazley-Green was appointed AA Defence Commander (AADC) with a Gun Operations Room (GOR) at Harwich:[21] (The Royal Navy submarine depot ship HMS Cyclops in Harwich harbour was designated as AA site H4 under the GOR) On 17 October the regiment fired its first rounds in anger, when sites H2 and H3 engaged an aircraft identified as hostile.

In addition, 4 Light AA (LAA) Bty was attached, manning eight static and four mobile Bofors 40 mm guns sited round Le Havre.

[34][36] By 8 June, under renewed German attacks, the 1st Armoured and the 51st (Highland) Infantry Division and other assorted British forces withdrew to the Seine.

[39] With the enemy closing on Le Havre, the 51st (Highland) Infantry Division was cut off and forced to surrender, 3 AA Bde was ordered to evacuate.

On the night of 11/12 June 246 Bty disabled their static guns and boarded the Southern Railway ferry SS Brittany, which took them to Cherbourg-en-Cotentin.

From Cherbourg, RHQ and the two batteries without equipment were shunted by train between Nantes and Rennes before being evacuated from St Nazaire aboard SS Duchess of York and reaching Liverpool on 18 June.

247 Battery, operating directly under 3 AA Bde, deployed to defend Rennes and then moved to St Nazaire on 18 June, when it dumped its disabled guns in the dock and boarded SS Glenaffric and was evacuated to Plymouth.

With great difficulty, the section got all the secret equipment aboard the SS Marslew which sailed on 18 June and docked at Falmouth, Cornwall, the following day.

Two sections of 248 Bty spent over a month at Cardiff, with the guns in action against almost daily air raids during the Battle of Britain.

By the end of the month the responsibilities at Pembroke Dock and Cardiff had been handed over to other units and the whole of the regiment was deployed around Swansea, with a GOR established.

The position was completed and guns mounted in December, and a similar 4-gun site was begun in January at Ravenhill north of Swansea.

On the latter night there was confusion between the Sector Operations Room at RAF Pembrey and the Swansea GOR, resulting in the guns ceasing fire between 20.20 and 21.10, leaving the town centre unprotected.

[4][46][65] On 3 January 1942, 79th (HY) HAA Rgt was ordered to convert from a four-battery static organisation to a three-battery mobile unit in preparation for overseas service.

A month later the relieved regiment returned, and 79th (HY) HAA Rgt moved to Hitchwood Battle Camp in Hertfordshire for infantry training.

[69] During October the regiment was relieved of duties under AA Command and came under War Office (WO) Control at Uttoxeter while the necessary ancillary units arrived.

[77] Enemy resistance in North Africa ceased on 12 May 1943, but AA defence of the Algerian ports continued while they were used to prepare for the invasion of Sicily (Operation Husky).

Meanwhile, 79th (HY) HAA Rgt prepared for service in the Italian Campaign with training in mobile warfare and ground shooting.

[80] 79th (HY) HAA Regiment disembarked from transports at Naples between 27 March and 14 April to join 52 AA Bde defending the Foggia Airfield Complex.

Lt-Col Dickinson was appointed Deputy AADC for the Spinazzola Group of airfields, with batteries of 64th LAA and 106th HAA Rgt under command.

[84][85] In July the regiment was withdrawn from operational duties and began mobile training pending a move to Allied Force Headquarters in northern Italy.

Calls for ground fire slackened after US IV Corps crossed the Arno on 1 September, and the batteries took up positions on the far side of the river.

The MDC was being formed at the time to provide trained military support for the Civil Defence Corps and Fire Services on a regional basis.

The men from 479th HAA Rgt provided the basis for 8th (Hertfordshire and Cambridgeshire) Battalion of the MDC, with HQ at Barnet, recruiting from across both counties.

When the MDC was disbanded in February 1959 those members of 8th Bn who wished to continue in the AER transferred to the Royal Army Ordnance Corps.

[2][5][122] A memorial tablet to the men of all four Hertfordshire Yeomanry artillery regiments who died during the Second World War was unveiled in St Albans Abbey on 19 September 1954.