In the 1930s it re-roled as an anti-aircraft unit and served in World War II, including North-western Europe from June 1944 to May 1945.

[1] In 1900, men of the battalion volunteered for service in the Boer War that which had been raging since 1899 and contingent sailed for South Africa in February.

The battalion was involved in the first day of the Battle of the Somme on 1 July 1916 and the brigade they were part of sustained very severe casualties in the Attack on the Gommecourt Salient.

[7] During the First World War, Captain Albert Ball – fourth ranking ace of the Royal Flying Corps – had been awarded the Victoria Cross for his actions in 1916–1917 while seconded from the Robin Hoods.

[34][35][36][37][38] In early 1944 the regiment was in the North of England under 31 AA Bde, which was one of the formations earmarked for the Allied invasion of Normandy, Operation Overlord.

369 Bty was disbanded on 23 February, and the remainder of the regiment underwent special training to support Night fighters over the Normandy beachhead.

[39][40][41] After D-Day (6 June) the regiments of 31 AA Bde waited in England for their turn to embark for Normandy to join 21st Army Group.

On 1 August the regiment left its staging camp and deployed in the AA role round RAF Colerne in Wiltshire, then on 6 August it moved to RAF Middle Wallop and relieved 69th (3rd City of London) S/L Rgt, establishing Regimental HQ (RHQ) at Fonthill Abbey, near Tisbury, Wiltshire.

On 24 August the regiment was relieved by 54th (Durham Light Infantry) S/L Rgt and concentrated around Tisbury, where it was at 6 hours' notice to move to its marshalling area.

Cronin moved to Storrington, West Sussex, and then on 12 September to an embarkation marshalling area at Whipps Cross Camp, near London.

From there it embarked at Royal Albert Dock aboard SS Empire Swordsman and disembarked by landing craft at Arromanches-les-Bains in Normandy on 18 September.

366 S/L Battery under the operational control of 56 US AA Artillery Bde set up 90 cm lights to illuminate any surface craft trying to approach Antwerp and allow LAA guns to engage them.

With experience drawn from defending against the V-1 attacks on Southern England (Operation Diver), GHQ AA Troops with 21st Army Group had a contingency plan for this, known as 'X' defences.

This involved three lines of warning stations in the path of the V-1 attacks, then heavy AA guns at least 10 miles from the target cities.

Searchlights were deployed to aid the guns at night, and to mark the boundaries of the X defence areas to warn off friendly aircraft.

British units took responsibility for Brussels, but the two batteries of 42nd S/L Rgt deployed at Antwerp were under the command of the US 50th AA Artillery Brigade.

[42][43][45][46][47] With experience, the defenders improved their effectiveness: in Christmas week, the Antwerp X defences plotted 209 missiles approaching the city, of which 171 came from directions in which it was safe to employ AA guns; of these 102 were engaged and 61 destroyed.

[49] In the last stages of the war, 42nd S/L Rgt moved into Germany to defend the Rhine bridges against conventional air attack, with 366th Bty still deployed on the South Scheldt estuary.

[50] After VE Day the regiment moved to Hamburg to begin occupation duties; in July, 367 S/L Bty was called out to suppress rioting between German and Italian dock workers.

[25][54] Honorary Colonels of the battalion included:[1][7][55] The actions of the 46th (North) Midland Division at the Hohenzollern Redoubt on 13 October 1915 are marked by two memorials.