The 1st (Hanover Square) Middlesex Artillery Volunteer Corps was raised on 16 July 1860 during the great surge of enthusiasm after an invasion scare that saw the creation of many Rifle, Artillery and Engineer Volunteer units composed of part-time soldiers eager to supplement the Regular British Army in time of need.

A second battery was formed on 22 September 1860[2] Initially, the unit was based in Regent Street, but by November 1860 its headquarters (HQ) was at No 3 Hanover Square in London's Mayfair district.

In 1866, members of the 1st Middlesex Artillery Volunteers were accused of fundraising for Governor Edward Eyre of Jamaica, whose brutal suppression of the Morant Bay Rebellion in the island had divided political opinion in London.

[7] At the great Easter Volunteer Review at Brighton Racecourse in 1862 (involving the sham 'Battle of White Hawk Down'),[8] the 1st Middx AVC appeared with their field guns pulled by horses supplied for the occasion by Messrs Pickfords, the removal contractors.

[11] But many Regular officers refused to believe that part-timers could be effective as field gunners, and despite the eloquent arguments of Lt-Col Shakespear of the 1st Middlesex Artillery Volunteers, the Secretary of State, Edward Cardwell, refused to allow the upkeep of guns, harness or horses to be paid from the Artillery Volunteers' government grant.