Enthusiasm for the Volunteer movement following an invasion scare in 1859 saw the creation of many Rifle, Artillery and Engineer Volunteer Corps composed of part-time soldiers eager to supplement the Regular British Army in time of need.

In 1863 these units, together with the AVCs from Orkney and Ross-shire, were formed into the 1st Administrative Brigade, Caithness Artillery Volunteers, with its headquarters (HQ) at Wick, to which other Caithness units were added as they were formed:[3][4][5][6][7][8][9] Once a 5th Orkney AVC had been raised in 1865 there were moves for Orkney to have its own brigade, and this was organised on 15 March 1867; at the same time the 1st Ross-shire joined the 2nd Ross-shire in the 1st Inverness-shire Admin Brigade.

In their place, the 1st Caithness Admin Brigade took over the AVCs in Sutherland from the Inverness-shire brigade, giving it the following organisation:[4][5][6][7][8][10][11] Volunteer corps were consolidated into larger units on 1 May 1880, when the 1st Admin Brigade became the 1st Caithness (Caithness and Sutherland) Artillery Volunteers, with the individual corps as numbered companies:[4][5][6][7] From 1 April 1882 all AVCs were affiliated to a division of the Royal Artillery (RA), the Scottish Division in the case of the 1st Orkney, moving to the Southern Division when the numbers were reduced on 1 July 1889.

[12] When the Volunteers were subsumed into the new Territorial Force (TF) under the Haldane Reforms of 1908,[13][14] the unit was disbanded on 31 March.

[4] The first uniform of the Caithness corps was similar to that of the Royal Artillery, but with scarlet cuffs and white cord and piping.