A 1st Administrative Brigade had been formed the previous year, but the number of units in the county had continued to grow and they were split between the two headquarters.

[2][3][8] In February 1880, the AVCs were consolidated, and the 2nd Devonshire Administrative Brigade became the 6th (soon changed to 2nd) Devonshire AVC with the following composition:[2][3][4] In 1893 the HQ and Nos 1 and 3–9 Companies were based at 14 Paradise Place at Stoke in Devonport,[9] and No 2 Company was at Ridge Park Road, Plympton,[10] and Fore Street, Salcombe at Fore Street, Salcombe.

[11] In the same year the War Office Mobilisation Scheme had allocated the 2nd Devonshire Artillery Volunteers to the Plymouth fixed defences.

A new cadet corps was formed at Plymouth and Mannamead College in 1900, but was transferred to the 2nd (Prince of Wales's) Volunteer Battalion, Devonshire Regiment in 1907.

[20] The unit was mobilised in the South Western Coast Defences on the outbreak of World War I in August 1914, and raised two additional companies, Nos 1 & 2.

[26][27] By the autumn of 1914, the campaign on the Western Front was bogging down into Trench warfare and there was an urgent need for batteries of heavy and siege artillery to be sent to France.

The WO decided that the TF coastal gunners were well enough trained to take over many of the duties in the coastal defences, releasing Regular RGA gunners for service in the field, and 1st line TF RGA companies that had volunteered for overseas service had been authorised to increase their strength by 50 per cent.

Equipped with 9.2-inch howitzer it went out to the Western Front in January 1916 and served there for the rest of the war, latterly in 34th Brigade, RGA, supporting First Army.

The TF was reorganised as the Territorial Army (TA) in 1921 and the unit was redesignated the Devonshire Coast Brigade, RGA, with 157 and 158 Btys.

As the TA expanded in the months leading up to the outbreak of World War II, a new 193 Heavy Battery at Falmouth, Cornwall was added to the regiment in August 1939.

[2][14][38] When war was declared on 3 September 1939, the Devonshire Heavy Rgt was responsible for the following guns:[42] Plymouth: Falmouth: With the threat of invasion after the Dunkirk evacuation, the coastal artillery defending the United Kingdom was greatly increased.

[14][47][53][57][51][60] When VIII Corps was assigned to 21st Army Group in early 1943 for the forthcoming Allied invasion of Normandy (Operation Overlord), the Plymouth defences came under 'South Western District Coast Artillery' in Southern Command.

By this stage of the war many of the coast battery positions were manned by Home Guard detachments or were in the hands of care and maintenance parties.