Mobilisation The units of the Welsh Division had just departed for their annual summer camp when the order to mobilise was received on 4 August 1914. They then returned home and assembled at their drill halls to mobilise. The Welsh (Carnarvonshire) Heavy Battery mobilised at Bangor under the command of
Major W.H. Hughes, who had held the command since 20 December 1913. The battery immediately went by train to its war station at
Scoveston Fort, above the
Royal Navy anchorage of
Milford Haven. The battery's horse purchaser was able to impress and buy enough horses for the guns and ammunition column in just four days. The men spent September digging gun positions around the anchorage. The two sections being widely separated – a wagon taking 48 hours by road to travel between
Pembroke Dock and Scoveston Fort – battery training proved difficult. By 11 August the Welsh units had completed their concentration and TF members were invited to volunteer for Overseas Service. Four days later the
War Office (WO) issued instructions to separate those men who had signed up for Home Service only, and form these into reserve units. Then on 31 August the formation of a reserve or 2nd Line unit was authorised for each 1st Line unit where 60 per cent or more of the men had volunteered for Overseas Service. The titles of these 2nd Line units would be the same as the original, but distinguished by a '2/' prefix. In this way duplicate batteries, brigades and divisions were created, mirroring those TF formations being sent overseas. The Welsh Hvy Bty began forming its 2nd Line battery in October. Finally, on 10 February 1916 the battery was warned for overseas service and on 16 October it moved to
Woolwich to mobilise for overseas service with the BEF. It embarked on the transport
Karnak at
Southampton Docks on 26 February, but after three days at anchor was landed again. It re-embarked on 2 February and landed at
Le Havre next day. It then went by train to
Doullens and by road to join 23rd Heavy Artillery Group (HAG) in
Third Army. It went into action on 17 March in the
Vimy Ridge area. Major Hughes was evacuated to hospital on 26 March, and Maj G.H. Nugent arrived next day to take command. During May, Maj Nugent took over temporary command of 23rd HAG and
XVII Corps Counter-Battery (CB) Group. 1/1st Welsh Hyv Bty remained active on this front through the summer. On 13 August it was heavily shelled and Maj Nugent was wounded; Capt G. Brymer assumed command and was confirmed in the position on 15 September. The battery was in the bombardment of
Beaucourt Redoubt between 05.05 and 08.30 on 3 September, and then engaged in CB fire. On 15 September (the
Battle of Flers–Courcelette) it assisted with CB fire in the direction of
Courcelette. On 3 October the two guns of Left Section were condemned as unserviceable and sent to the Ordnance workshops, being replaced by two Mk IV 4.7-inch guns. In December 1916 the WO decided that all heavy batteries should be composed of six guns. 1/1st Welsh Hvy Bty received its first four new 60-pdrs on 27 February, and then on 3 March it was joined by a section of one officer and 83 gunners from
200th Hvy Bty (newly arrived in France and immediately broken up) to bring it up to a six-gun establishment. On 7 March it fired off all its 4.7-inch ammunition and passed its old guns over to
1/1st Highland Hvy Bty. Next day it began a four-day march to
Verquin to join 31st HAG in First Army on 12 March. That night it emplaced three guns at
Bully-Grenay, the other three following on 16 March. As the
Arras Offensive continued, the battery advanced three guns to a new position at Cite Calonne on 21 April, the others moving up to Rollencourt on 27 April, and the wagon lines to Petit Sains on 12 May. The battery suffered a number of casualties. The half battery at Cite Calonne was heavily shelled on 11 May when two guns were put out of action, and again on 14 May, this time without casualties.
Spring Offensive Second Army HQ was sent to the
Italian Front at the end of 1917, and Fourth Army took over the
Ypres Salient, with 1/1st Welsh Hvy Bty transferring to 53rd HAG on 18 December. Second Army HQ resumed command of the Ypres sector (including 53rd (Mixed) Bde RGA), in March 1918 and was soon involved in the
Battle of the Lys, the second phase of the
German spring offensive that involved great loss of ground and rapid retreat for much of the artillery. The German advance on Second Army's front was halted on 29 April.
Hundred Days 1/1st Welsh Hvy Bty received an extended rest from 27 July to 17 August. The battery was placed in suspended animation in 1919. It was reduced to a
cadre and went to
Georgetown, South Wales, for disbandment on 19 September 1919. ==Postwar==