[2] While serving in the Frontier Commission, along with friend and fellow archaeologist William Loftus and a detachment of troops, he rode across the desert and marshes of Chaldaea from the Euphrates to the lower Tigris, observing remains as they went.
During their travels Churchill made extensive detailed drawings and sketches, which were subsequently deposited in the British Museum[3][4] and the Geological Society.
[7] As Secretary and Interpreter on the Staff of the British Commissioner with the Turkish Army in Asia, he took part in the defence of Kars, and after its capitulation to General Mouravieff in November 1855 was for a time a prisoner of the Russians.
Mr Churchill, the General's secretary, worked hard at this department; and never were his practical, business-like talents more needed, or more effectively exercised.
My secretary, Mr. Churchill, an attaché of Her Majesty's mission in Persia; he directed the fire of a battery throughout the action, and caused the enemy great loss.
[16] He also worked on anti-slavery issues with Sultan Majid who had consolidated his power around the East African slave trade, and stopped much of the commercial slavery then still occurring on Zanzibar.
However his recovery was short lived and in 1869 his Vice Consul and physician John Kirk advised him to leave for London for the sake of his health.