Several of the other early officers were retired from the British or East India Company's armies, or prominent personages in the county, including Captains Sir James Sibbald David Scott, 3rd Baronet, and the Hon.

The unit's Major was William Augustus St Clair, formerly of the Bombay Horse Artillery, who succeeded at Lt-Col Commandant on 2 May 1861.

There were moves to reform the Auxiliary Forces (Militia, Yeomanry and Volunteers) to take their place in the six Army Corps proposed by St John Brodrick as Secretary of State for War.

[15][16] Under the sweeping Haldane Reforms of 1908, the Militia was replaced by the Special Reserve, a semi-professional force whose role was to provide reinforcement drafts for Regular units serving overseas in wartime.

[7] An engraved print of June 1854 shows the Royal Sussex Militia Artillery at gun practice at Southover, Lewes.

The wooden gun shed from which they are shooting has mock fortress embrasures facing the firing range over the South Downs.