It continued in the postwar Territorial Army (TA) as a heavy anti-aircraft artillery regiment until amalgamated with other Welsh units in 1954.

[10] Dillwyn was succeeded in command by John Crow Richardson of Glanbrydan Park, who had enlisted in the unit as a private in December 1859 and was commissioned as ensign in 1864.

[11][clarification needed] A detachment of volunteers from the battalion served in the Second Boer War, winning the unit its first Battle honour: South Africa 1900–1902.

[17][19] On 9 March 1911 Lord Ninian Crichton-Stuart, second son of the 3rd Marquess of Bute of Cardiff Castle, was commissioned Lt-Col in the battalion and took command the following year.

[19] Based at Boulogne and Saint-Omer the men were employed in handling railway traffic, escorting prisoners, and providing carrying and burial parties.

At 20.00 on 1 October the 1st Welsh launched a surprise attack on 'Little Willie' trench, a section of which they captured despite heavy casualties.

[2][29][30] One report stated that Crichton-Stuart was preparing to lead a counter-attack to recover his close friend Maj Reginald Browning of 1/6th Bn who was still in the abandoned trench.

The 2/6th Welsh were absorbed by the 2/5th (Flintshire) Bn, Royal Welch Fusiliers, which remained in home defence until it was disbanded in March 1918.

[6][38] In the 1930s, the increasing need for anti-aircraft (AA) defence for Britain's cities was addressed by converting a number of TA infantry battalions into searchlight (S/L) units.

45 AA Brigade's units – particularly the widely spaced S/L sites – were ordered to find rifle and LG detachments to guard against possible attacks by German paratroopers.

67th S/L Regiment was ordered to have three "flying columns" of riflemen in lorries ready at 15 minutes' notice to reinforce these detachments.

At this time the company HQs were:[44][45] After the British Expeditionary Force was evacuated from Dunkirk, the German Luftwaffe began almost nightly minor air raids, often by single aircraft, against the dock facilities, steelworks and ordnance factories of South Wales, or minelaying in the Bristol Channel, though the daylight Battle of Britain was mainly fought over Southern England.

The S/L layout in South Wales supported the AA guns and Royal Air Force (RAF) night fighters.

On 28 June, 67th S/L Rgt was ordered to hand over its VPs at Port Talbot to a new LAA unit and move the detachments to Clanna, near Bridgend, to increase the S/L concentration in the Cardiff Gun Defence Area (GDA).

[6][39][40][48][49] During the summer, the AA defences of South Wales were bolstered by a number of units that had been re-equipped after evacuation from Dunkirk and Norway.

[46][55][56][57] After a busy period for the AA defences of South Wales in early May 1941, the Blitz effectively ended in the middle of the month.

[46][59][60][61][62][63] In mid-1943, AA Command was being forced to release manpower for overseas service, particularly Operation Overlord (the planned Allied invasion of Normandy).

[46][51][64][65][66] By late 1944, the Luftwaffe was suffering from such shortages of pilots, aircraft and fuel that serious aerial attacks on the UK could be discounted and the War Office began reorganising surplus AA regiments into infantry battalions for duties in the rear areas.

[6][39][49][40][67][68] Meanwhile 21st Army Group fighting in North West Europe was suffering a severe manpower shortage, particularly among the infantry.

It went to North West Europe in May and did duty with 306 Infantry Brigade on the Lines of Communication for 21st Army Group after VE Day.

After several more rounds of mergers the lineage is continued in 211 (South Wales) Bty in today's 104th Regiment Royal Artillery.

[7][11][clarification needed] During the First World War, members of the 6th Welch were presented with ribbons in the regimental colours of white/red/dark green by the CO's wife, Lady Crichton-Stuart.

[84][85] There is a bronze statue of Lt-Col Lord Ninian Crichton-Stuart, MP, at Gorsedd Gardens, Cathays Park, in Cardiff.

[86] Crichton-Stuart's coat of arms appears on a shield in the Chamber of the House of Commons along with those of 18 other MPs who died in the First World War.