It was amalgamated with another battalion in the 1920s but regained its independence in time for World War II, when it served in home defence and supplied reinforcements to the forces fighting overseas.

On the same date, Sir Joseph Bailey, 2nd Baronet of Glanusk, MP, who had been commissioned as a lieutenant in the 3rd RVC on 14 February 1861, was appointed the battalion's Honorary Colonel.

[7][8][9] The Reverend William L. Bevan, later Archdeacon of Brecon, was appointed Honorary Chaplain to the 3rd RVC on its formation, and continued in this role with the battalion until his death in 1908.

[7] Under the 'Localisation of the Forces' scheme introduced by the Cardwell Reforms of 1872, Volunteers were brigaded with their local Regular and Militia battalions – for the Brecknockshire Battalion, this was in Sub-District No 25 (Counties of Cardigan, Radnor, Brecon and Monmouth) of Western District, with the following units:[7][10] Because there had been no regular regiment affiliated with these counties, the 2nd Warwickshire was arbitrarily assigned.

The Stanhope Memorandum of December 1888 proposed a more comprehensive Mobilisation Scheme for volunteer units, which would assemble in their own brigades at key points in case of war.

[7][27] After Black Week in December 1899, the volunteers were invited to send active service units to assist the Regulars in the Second Boer War.

[28][29] The company assembled at Brecon Barracks for intensive training, with emphasis on musketry, and Capt J. Llewelyn Phillips of the 2nd VB was appointed to its command.

The company left Brecon by train on 14 February to link up with the 1st VSC of the Welsh Regiment at Newport, but the train was delayed by snow and the company only just reached Southampton Docks in time to catch the Union Line steamer Greek was preparing to sail with the 1st VSC Welsh regiment and large numbers of other troops.

Covered by their own artillery, Maj-Gen Archibald Wavell's 15th Brigade, including 2nd SWB, attacked the kopjes on which the Boer guns were in action.

On 10 June most of 2nd SWB, including I Company, marched out to Vredefort Road, north of Rhenoster, where De Wet's Commando was carrying out attacks along the line of the newly reopened railway.

On 7 July most of the battalion moved on to Rhenoster, leaving B and I Companies at Vrederfort Road, where they were kept busy digging entrenchments on the kopjes commanding the town and railway.

[29][32] Hart's column returned to Krugersdorp on 30 September, and next day the 1st VSC left 2nd Bn SWB and began the first stage of what was expected to be its journey home.

However, the war was not ending as expected, and the company was repeatedly delayed and diverted to duties on the lines of communication, and it was not until 27 April 1901 that it finally embarked on the SS Idaho at Cape Town.

In October the company was attached to Col Hickie's Flying Column, whose task was to protect Royal Engineers and labourers extending the blockhouse line from Klerksdorp to Ventersdorp under threat from Liebenberg's Commando.

During its short period of service the company served in garrison and blockhouse duties, After the Treaty of Vereeniging it was released and sailed home to a military and civic reception at Newtown on 2 August.

On 15 August, the War Office issued instructions to separate those men who had signed up for Home Service only, and form these into reserve units.

By the time the Brecknockshires arrived, war had been declared with the Ottoman Empire (Turkey) and Turkish forces in Yemen were threatening Aden, one attack already having been driven off.

In June 1915 Turkish forces attacked Perim island in the Red Sea, and advanced on Lahej, 20 miles (32 km) north of Aden.

An 'Aden Moveable Column' was organised, consisting of about 1000 infantry (the largest contingent, over 400 strong, from the 1/1st Brecknockshires) with the Aden Troop of Indian cavalry and artillery support.

[40][45] The Moveable Column set out on 3 July and marched to Sheikh Othman, but a number of requisitioned cars were sent on ahead carrying a few infantry to reinforce the Aden Troop as the advance guard at Lahej.

There was confused night fighting (the Battle of Lahej) in which the sultan, Sir 'Ali II ibn Ahmad al-'Abdali, was mortally wounded, and the camel drivers fled, taking their loads with them.

The reinforcements from Egypt recaptured Sheikh Othman on 21 July and fortified the position to secure the water supply, but a Turkish garrison remained in Lahej until after the end of the war.

The Afghan War ended in August 1919, but it was not until October that the 1/1st Brecknockshire Bn was released from its internal security duties and the men could be sent home to be demobilised.

[4][38][40][48] In November 1916 the 2/1st Brecknockshire Bn was absorbed into 2/7th (Merionethshire & Montgomeryshire) Battalion, Royal Welch Fusiliers (RWF) at Wrentham, Suffolk in 203rd (2nd North Wales) Brigade.

In the summer of 1917 its battalions began to be replaced by units of the Training Reserve, and 2/7th RWF was disbanded on 12 September 1917, its personnel being distributed amongst the rest of the brigade.

In March 1918 it moved to Kinmel Camp in North Wales, and then in June 1918 to Herne Bay in Kent, where it remained for the rest of the war.

[56][57] However, on 1 December 1941 the division was placed on a lower establishment; this meant that it was not going to be sent overseas for the foreseeable future, and it became a static coast defence formation in Dorset under V Corps.

As the invasion threat receded, the lower establishment divisions became sources of units and drafts to reinforce the fighting formations overseas.

[5] However, in 1905 the SWB was authorised to resume the traditional grass green facings of the old 24th Foot; these were also worn by the Brecknockshire and the 3rd Monmouth battalions.

[70] A brass plate was similarly put up in Christ Church, Mhow, listing the other officers and men who died while the battalion was serving in India, 1915–19.