The Royal Engineers (RE) had developed an extensive anti-aircraft (AA) searchlight (S/L) organisation during World War I,[1][2][3] but this was quickly reduced after the Armistice.

Although destined to become the largest Regular unit of the RE during the inter-war years, its initial strength was three non-commissioned officers (NCOs) and four sappers under the command of a lieutenant of the Royal Field Artillery.

Elliott became its first RE commanding officer, and after nearly two years, it received substantial reinforcements, including troops experienced in operating lorry-mounted searchlights during the Irish War of Independence.

[4][5][6][7] The main responsibility for AA defence of the United Kingdom was entrusted to the part-time Territorial Army, which developed a large-scale organisation under Anti-Aircraft Command before the outbreak of World War II.

In 1938 it was decided that all coastal and AA searchlights, which operated alongside the Royal Artillery (RA), would become the responsibility of that corps; however, the transfers had not been completed when war was declared in September 1939.

[1] On arrival in France, the battalion deployed to protect the BEF's No 2 Base Sub-area at Nantes, but at the end of the month it moved up to Fauquembergues, where its lights cooperated with night fighters of No 60 Wing, Royal Air Force in the Aircraft Fighting Zone (AFZ) bounded by Bergues, Cassel and Guisnes (just inland from the ports of Boulogne, Calais and Dunkirk).

[12][14] 3rd Searchlight Battery, RA, had mobilised at Portsmouth, and sailed from Southampton, disembarking on 16 September at Brest, where it was delayed for a week awaiting the arrival of much of its transport.

[17] From late December, the regiment provided two sections at Boulogne and Dunkirk to cooperate with Light AA (LAA) guns in trying to prevent German seaplanes from dropping Parachute mines in the harbours.

On 17 May it detached a group of riflemen with Boys rifles to 5th AA Brigade HQ at Lens (these never returned to the battery during its stay in France) while the remainder joined the Bethune canal guards.

The 1st Bn Queen Victoria's Rifles (QVR), the lead unit of 30th Infantry Brigade, arrived by sea on 22 May, just before advanced German troops began probing the defences.

But ground attack was now the biggest danger, and the S/L men had to man the perimeter as infantry, a role for which they (mainly older Territorials, raw militiamen and a few ex-RE reservists) were untrained.

[37] Neave with a sergeant and a sapper, failed to blow the apparatus up with Gun cotton, but two French drivers abandoned and set on fire their tankers of aviation fuel and the resultant blaze destroyed the equipment successfully.

His THQ, including a number of stragglers from other units, came under attack by German tanks and aircraft in the evening and he fell back to a small farm in a nearby wood.

Although the tanks withdrew, Dothie guessed that they would bring up reinforcements and he ordered his men to withdraw, covering their crossing of some open ground with a Bren gun.

However, he and the QVR Bren gunner found themselves cut off on the wrong side of the open ground and could not get back to the rendezvous until after dark, by which time the rest of the party had made their way to Calais.

Finding that the Channel Islands were already in enemy hands, he returned to Cherbourg Harbour before making a second successful attempt to reach England by boat.

William Dothie got back on 2 August, and Airey Neave later made the first successful British escape from Colditz Castle, reaching England in April 1942.

On return to the UK, 3rd S/L Bty was quickly re-equipped with a reduced number of S/Ls and sent to Gibraltar in July to bolster the AA defences of the naval base against raids by Vichy French and Italian bombers.

For example, 477th S/L Bty had been formed at 217th Searchlight Training Regiment at Bradbury Lines, Hereford, with a cadre of experienced men from the Territorial 59th (Warwickshire) S/L Rgt.

[19][48][52][53][54][55][56] The regiment supplied a cadre of experienced officers and men to 230th S/L Training Rgt at Blandford Camp where it provided the basis for a new 545 S/L Bty formed on 16 January 1941.

[49][57][58][59] The city of Canterbury was raided in the so-called Baedeker Blitz soon after the regiment arrived in the area, and thereafter the AA defences of Southern England were severely tested by the Luftwaffe's 'hit-and-run' attacks along the South Coast from the summer of 1942.

[63][64] Between 21 January and 14 March 1944 the Luftwaffe crossed the S/L belt of SE England to carry out 11 night raids on London in the so-called Baby Blitz.

However, by March 1944, AA Command was being forced to release manpower for service overseas, including the planned invasion of Normandy (Operation Overlord).

The AA resources in SE England were strongly reinforced in Operation Diver, the S/L belt being thickened up both to cooperate with RAF Night fighters and to use their S/L Control (SLC or 'Elsie') radar to guide LAA guns.

[68] By the end of 1944, 21st Army Group had advanced to the Belgium–Netherlands frontier, and required AA reinforcements to protect the vital port of Antwerp and its approaches up the Scheldt Estuary from bombing (including parachute mines) and 'Divers'.

[71][73] 76th AA Brigade was ordered to cease fire on 3 May 1945 when a local truce came into effect to allow supplies to be airlifted to civilians in the enemy-occupied Netherlands (Operation Manna).

Its units, including the whole of 1st S/L Rgt, then returned to the mainland from the Scheldt islands and concentrated north of Antwerp before moving into Germany in June to garrison the Dortmund–Bochum area.